Well I picked up TW2 for my Xbox and am playing through it now; the old adage its hard to go back when you've played the superior sequel is true in this case too.
Its not unplayable (Im getting enough satisfaction from it that I am happy with the purchase), but you can REALLY see where they took stuff that didnt work well and improved it for TW3.
Some of the things are a little interesting from a lore perspective (touching the medallion for Witcher senses as opposed to Witcher 3 where you just use them for instance).
Not being able to jump is really annoying. Very path driven. Side quests feel extraordinarily optional and that in a lot of cases Im not even sure I received any money or EXP for completing them. The story feels much smaller, when given the context of the situation it should feel a lot bigger IMO, but that may be due to "hub" design of the place you visit. Physically its not nearly as large in scale.
Combat is fine, I havent had any issues there. Signs, alchemy, and crafting seem entirely optional. I dont general use any of them except for Igni in battle.
One thing that has greatly improved is the menu system, its a bit of a mess in TW2
The story is pretty convoluted, and I find quest markers are either missing entirely or not visible at all. For instance its like "go destroy nekker nests" but it doesnt even give a hint as to where they might be. A little frustrating. Things like this coupled with the limitations of the hardware when it was designed make for a lack-lustre experience at times. One mission is "search houses for X thing". No indication which house in the town its in, and a load screen when going into and out of every single house makes for long tedious mission.
All in all im playing it mostly for the story, and its probably going to lead me into my first TW3 replay, so thats not a bad thing.