After completing PoE on hard then PotD I went out to try TCS with a pale elf monk. It forced me to play with a different style then I'd used with my other run-throughs. It also gave me perspective on how wide PoE is with different styles of play. I've read that the game provides too much gold & xp, I feel that the amounts are good in that you can skip wide a good amount of loot and quests and still have enough of either.
The one issue I've run into on all three of my runs is, what I feel is, an over abundance of different weapon types. Perhaps I will need to run through with all classes but many of the weapon types do not seem useful. I will break down each weapon type and my experiences with each.
Hunting Bows - Very useful for a high level hunter that uses the stun on hit ability to lock down a mob and provide surprisingly high damage with all the bonuses that the class gets.
War Bows - Used them on my cipher only until I was able to get a blunderbuss. I suspect they would work just as well on hunters as hunting bows, though they wouldn't have the lock down stun due to larger rof.
Crossbows - Only useful in lower levels until arbalests become available. Honestly regular crossbows could be dropped from the game and I feel that there wouldn't a noticeable difference. Their damage is lower then arbalests and lack the knockdown on crit, while being much slower then bows.
Arbalests - One of the kings of the battlefield. High damage, knockdown on crit and great range. What's even better is they don't have the decrease in accuracy that firearms have. That isn't much of an issue except on PotD where you want every bit of accuracy that you can get.
Blunderbusses - Great cipher weapon on difficulties below PotD. Their multiple projectiles can add up to good damage and generate mounds of focus if they all connect. On PotD, at least for ciphers, the accuracy penalty makes them too unreliable. A niche weapon that shines for only one class.
Pistols - I feel that they're also a niche weapon as arbalests have pistols on range, knockdown and interrupt. They do work well as a ranged weapon for rogues. Especially since pistols are in the ruffian tree with the other strong rogue weapons.
Arquebuses - I'll refer to them as rifles even though that isn't correct in any way, rifle is easier to type. They are the ranged weapon on difficulties below PotD. High damage and DR bypass allows a party to melt tough enemies in a single volley. On PotD I found that it was better to use Arbalests for the higher accuracy, expect for Durance if you take his accuracy buff for rifles.
Magical Implements - Wands, Scepters & Rods can all be lumped together. Forgettable. It's odd that there are three types of a weapon type that is only useful at low levels. While the aoe that you can gain from the blast talent is kinda nice at those low levels, you are spending a talent on weapons that has a low base damage that makes it a liability once tougher monsters are encountered. It's iconic for wizards to have their magic wands but they feel poorly implemented in PoE. Better to have your wizard have an arbalest and do real damage.
Daggers, Rapiers, Flails - I grouped these three together as I didn't use these weapons during my play-throughs. Daggers and rapiers give accuracy which is nice, but their damage is too low and more damningly they are in the Noble talent tree. Both weapons seem they'd be useful for rogues, but the Noble talent doesn't provide any ranged weapon. Ruffian is such a wonderful talent for rogue that the accuracy bonus becomes a penalty when comparing stiletto with Ruffian vs dagger without Noble. While on difficulties below on PotD where accuracy isn't such an issue you'd want to use higher damage weapons anyway. As for flails, they suffer from being in the Adventurer tree so I never found a use for them.
Stilettos, Clubs and Monk Fists - All three are fantastic. Stilettos are amazing for rogues, 'nuff said. Clubs are useful to give to Eder as he has the Ruffian talent and it's easy to get Blesca's Labor which is an amazing weapon. Monk Fists I've seen threads that have said that they are underpowered due to lack of enchantments. On my TCS I used fists for the vast majority of the run. They were fast that allowed me access to my wound abilities quickly, the damage stayed competitive with weapons that were even slower then my fists and a good number of monsters doesn't have crushing DR.
Maces, War Hammers, Spears, Swords, Battle Axes - I grouped all these together as in my experience they are almost interchangeable. No group really shines over the others, very well balanced. It all came down to what unique weapon was better. Spears are nice for monks when you need piercing damage due to being in the Peasant talent. Other then that, unique weapons and talents determine which of these weapon types you'll use.
Sabres - Fantastic swords for either Eder or a rogue. High base damage with some amazing uniques to be found. As a bonus, they're in the Ruffian talent which includes several other wonderful weapon types.
Two-Handed Weapons - I have mixed feelings regarding these weapons. I certainly see that barbarians need the weapons with increased reach so they can inflict carnage while being safe behind the tanks. But, for tanks it makes no sense. Stick to sword and shield. On difficulties below PotD where melee combat is a bit more survivable they can be sort of cool for rp reasons, the drawbacks are too great to be useful otherwise. I've found that in PoE you want your attack speed to be balanced with damage. Too little damage and DR will make your many fast attacks not very useful. Too slow and if you wiff on an attack you could be waiting for awhile to be able to do damage again. With interrupts, knockdowns and all sorts of abilities that can stop attacks I've found if you want to do damage in melee two weapons is the way to go. Their talent increases weapon speed even more so you can have those attacks come at a reasonable speed while having adequate base damage. Two-handed weapons are too slow that when an armoured character attacks and gets interrupted, or whatever, the loss to combined party damage output is really felt. All these factors come together that I've just sold every one of these weapons I get.
While writing my rundown of the weapon types I realize that one problem that seemed to pop up now and again was the issue of the weapon talents. Ruffian and Soldier are great. Ruffian for rogues and soldier works for the majority of characters will be using ranged attacks, and tanks. Peasant is useful for some hunter builds and monks. Adventurer, Knight and Noble are all kinda garbage. Soldier and Ruffian have most of the good ranged weapons and two-handed weapons, except for barbarian, don't seem worth it. It leaves each of those three talents with maybe one or two weapons that you'd want to use throughout the game. Unless those weapons are key to an rp concept they can be safely passed on.
Those are my thoughts that seem to fit well in this post. The rest are "the music is so awesome!" or "these companion quests are so awesome" and even "the art is so awesome". Those will come later.