TW1: Great. I liked the potion system. The alchemy system wasn't as fun as Atelier's, and that specific materials weren't needed was a definite plus. No need for hunting down certain monsters to make Swallow potions. The UI was a bit off-putting, though that was easily remedied with The Rise of the White Wolf mod. To be honest, I actually dropped the game a year or two ago, and returned just last week, what with the UI mod being out (makes things much more crisp, and removes the dialogue box at the bottom!), as well as the hype for W3. I believe the mod overhauled a lot of the textures and characters, so they were decent. Of course, character animations were very stiff, something that was greatly improved upon in W2. Combat wasn't supreme, but it was still fun in its own way. I didn't see much use in any sign other than Aard (OHKO stun combo) and Igni, so I didn't invest in them. Font was a bit too small for the journal, however, which was remedied in W2. Story was overall good, though it was much less coherent compared to W2. W2 kept the adrenaline pumping, whereas W1 felt more like a single player MMORPG that had a decent story. For both games, I usually did all the side quests before the main quests. Ending was somewhat rushed, would've been nice to have a long epilogue, but since I knew it strikes into W2, it's fine as-is.
Overall, a good experience. Not the finest, nor most refined, but a game with enough base (esp. when modded with that nice UI) that I am looking forward to playing TW1 mods for it later on.
TW2: I liked the UI. I hear people despise it, though I actually liked it compared to most games'. Half of it actually felt very Vindictus-like. The journal entries were done well, and I actually read them for the most part (esp. monster bestiaries). Anyway, the UI felt very "new" compared to W1's original, which I liked. It's somewhat similar in nature to Vindictus's (well, mostly the font used and a few of the bluish tints here and there, some of the pop ups, the quest listings... etc.) which was a good plus. It'd be nice to see a Tera, Black Desert, RO2 (the initial one, not the Legend of the Second) UI, or Dragon Nest UI - these tend to be clean, with black backgrounds in most of the windows. Moving away from UIs, I never really used potions (besides Cat in the dark tunnel which I abhor more than Blight Town, and it does not make a fine Gutter - the Gutter feels pretty nice after you light all the torches) at all, and I feel that potions wouldn't find much use if they aren't at least 30 minutes long (or can be used on-the-fly). The animations are supremely better than TW1, though it's sad to see the maps feel much smaller than TW1's. There also wasn't a big city IIRC (no, ruined cities do not count). I am OK with rolling 24/7, since I played Demon's Souls before this. I can see why others might not like that (since they're not accustomed to it - Demon's Souls has more defense options than just rolling, with 100% physical defense possibilities from the get-go - attack options and variety are important) especially if they've never played a Souls game (rolling is best). I believe I saw a few i-frame backsteps in TW3's demo presentation. As a Souls player, I had little qualms with TW2's combat system, though it is indeed interesting that some people despise rolling (likely as a result of little variety in effective weapon movesets, attack and defense options) when rolling turned out to be king in DeS, DKS, and DKS2 (though guarding in all those games are effective, but shouldn't always be relied upon in PVP). Graphics for TW2 are great, I believe Durante has increased compatibility of Gedosato for TW2, so I'll see how it looks. Overall, the game is excellent, and, although it feels a bit short, it's simply because it's too good. I've played it twice, which is amazing, since I usually don't do that. Also, the side quests were great.
Well, I rambled on for much of these two, so the reviews are a bit incoherent. Still, tldr, both games are great, and shouldn't be missed out on. TW1 should be modded with The Rise of the White Wolf if you don't like the UI. Other than that, TW1 -> TW2 really shows how CDPR has greatly improved from 1 game to the next, and, if possible, may rise even further in TW3 (especially if the scale is much greater).
One thing I would really like to see is spawns changing (or being entirely removed from) an area due to clearing a quest. This happens at least once in TW1, and also happens on a larger scale (at least twice) in Dragon's Dogma, where the tunnel full of enemies became a merchant's tunnel (and had two guards patrolling) and that taking over one of the goblin forts allowed it to be occupied by allied troops. I like seeing land cleared, and spawns crushed, since I tend to feel afraid in areas such as TW2's forest, Dragon Dogma's tunnel, or TW1's many catacombs. Usually a sign of good atmosphere. Regardless, I feel incredible bliss when I conquer that area, and the undead stop spawning in those areas. Seeing that merchant, those soldiers, those brickmakers - they all remind me that I conquered that area. TW1's guard vs. kikimore in Viziman streets was also nice. I usually never see guards fighting monsters, unless it's in a modded Skyrim or a scripted event.
. I liked the game so much that, after my first playthrough on the Roche path, I immediately started another playthrough for the Iorveth one. And I hope to complete at least one more playthrough before TW3 comes out.