You don't typically buy a Samsung phone to get a high quality feel to it. My GS3 felt pretty plasticy and my LG Optimus G Pro doesn't feel a whole lot better. My friend's GS4 feels better and I've heard the GS5 feels fairly nice too.
That's all well and good but if I'm forking out £200+ for a phone I want it to feel robust. I wouldn't mind if they were a bit cheaper, but I'm sorry £470 for a plastic phone is a bit ridiculous. Yes, the spec of the Note 3 is great and the 1080p screen is gorgeous, but I just wish it felt a bit sturdier. You're right the S4 does feel better than the S3 (I have friends who have them) but I've been more impressed by HTC's build quality, certainly.
I honestly don't care though because I immediately bury the plastic in a cheap case off Amazon so it doesn't really make a difference to me how it feels.
True I guess. Usually I also buy (rubber) phone cases but I haven't bothered this time round for my 625. Whether I'll get one or not for my next phone, I don't know.
Windows phone looks decent but overall app support just isn't there for me and I like the way Android looks better.
Not a huge fan of the general Android layout/'explosion of colours' on this Samsung device but I guess Android is so customisable I could change that if I want. And other manufacturers have other UIs, I know. I prefer the look of HTC's TouchFlo (?) interface to Samsung's TouchWiz (?) interface for Android and even the stock look is nicer than this Samsung UI. HTC used to do a similar thing with Windows Mobile that made it look really cool.