I ran 5th edition for the first time today. I'll do an actual play report tomorrow, probably, but thought I'd jot down some comments on the system itself.
The first thing is that, in play, the whole thing is quite simple and actually feels quite a lot like Basic D&D - at least, the way I ran it. It wasn't fiddly or annoying. Put another way, I found that I could just wing quite a lot and it didn't seem to matter. I liked that.
The second thing is that it takes a little while to get your head around the way things work because it uses terms like 'proficiency', 'spell slot' and 'hit dice', which existed previously, in a different way. That was an odd choice, I think, although actually the way skills and proficiency works is fine.
The third thing is that, as expected, the way hit points are abstracted is quite jarring. In the session, one PC was attacked by a dog and lost all but 1 hp. It is hard to think of a dog attack as being anything other than: it savages your leg. Yet because of the way the system works, the character was practically back to full hp after the combat was over because of having an hour's rest. Now, look, I know hit points have always been abstract. I know you shouldn't think of them strictly as being health. But still, "I've been badly savaged by a dog... But I feel a whole lot better thanks to having a nice sit down!" just doesn't feel right to me.
The fourth thing is that, Christ, 5th edition PCs are tough. The three PCs in my game basically made mincemeat of all opposition because of the sheer power and versatility of the new magic system and the (it seems) deliberate attempt to make it easier to get hits in combat at low levels. Not that I'm complaining - it just is radically not the D&D I'm used to, and requires a different understanding of what a starting PC actually is: they're not vagrant wanderers who are just starting out; they're already established heroes.
The fifth thing is really that I'm pleasantly surprised. There are aspects of the system I dislike, and I don't think it would ever be my default, but it's simple, smooth, and easy to blag, and really, what more could you ask for?