That guy, Letho, is one of my favorite characters of ever. If you ever end up going back and getting to the end of that game, you'll get to fully appreciate why.
So, the Part 1 backwater town, Flotsam, does have a bit of an issue with some too-strong MOBsters around. I totally understand why they had to do that, though. Flotsam kind of drags on for a while, mostly for legitimate reasons, but some that admittedly felt a little bit filler-like. Either way, they had to include some parts of it that would still be somewhat challenging by the time you left. Nothing extreme like DA:I's dragons (or, some of the tougher surprise rift-holes around the Hinderlands area, which would totally kick that dragon's ass), because you never go back to Flotsam after leaving. But definitely some things that you'd have to play really perfectly to beat when you're first going in. (Personally, I'd played TW1 already going in, so I could pretty much tell on sight which monsters were probably too tough to take on without a couple more levels, and which weren't, so I didn't end up being terribly affected - but I can see how players who didn't have that kind of knowledge could find it problematic).
Me, I took the Roche path out of Flotsam, and found Parts 2 and 3 to be a really good, interesting time. I haven't (yet) gone back and tried the dirtly elf stink Iorveth's path. I'm told that if you do, it leads to a downright amazing Part 2, but transitions sort of awkwardly into Part 3.
Either way, the pacing and style of the reveals, as Geralt works on chipping away at the mystery of what the fuck is going on behind the scenes of all these assassinations, should end up engaging and keeping your interest really well - though it might take until after Flotsam for that to really start happening.
As for the intro sequence, most of it is totally skippable. I actually really liked it, though. Between Foltest's gruff charisma, Geralt's negotiations with La Fallette ("And who's going to guarantee our safety if we agree?" [flatly, shaking head] "No one."), and of course them Triss's boobs, well... safe to say that if the cinematic intro hadn't piqued my interest already, the prologue totally would have. That said, it can also be really tough, since you can't pick your fights and you start off without any gear (except people loading in a TW1 save, who potentially have a cool sword) or skill-point customization to speak of.
If you're like me, and insist on doing the hardest difficulty* all the time as a matter of principle, I can totally see how that would get frustrating. If you've got no problem with turning it down to easymode for the sake of enjoyment, it really ought to be fine. To this end, the tutorial sequence (should you choose to go through it), will recommend a difficulty level based on your combat performance at the end.
...shit, I've totally convinced myself. I'm gonna go back and do a Iorveth's playthrough now.
But, hey. Even if you find yourself actually not liking TW2, you really can't not love TW3. Clearly, I liked TW2 - but I've only put about 60 hours into it. For comparison, I've got over 430 hours put into TW3. (Playthrough, followed by replay into the first expansion, mind you). For whatever need there is to say that at this point.
Also. Side-note: I dunno if you can switch the language settings around on a console. But if so, I'd really recommend going with the Polish dub and subtitles over the English dub. The English VA isn't terrible or anything, but... it's just a lot less good. Obviously that's easy for me to say, on account of knowing the language anyway, but I got American friends that can back me up here. Just a suggestion.
*(Except for the ones that make you start the game over when you die. The hell with that business).
