While the film drags a little in the middle the rest of it is pretty much perfect. It's fast-paced, funny, weird, extravagant and doesn't seem worried by any boundaries or possible audiences.
Wright's a bit hit-and-miss for me, but when he fully commits to mood and atmosphere, he can be a formidable director. I'm not a 60s fan (at all), still I loved everything he conjured up in Last Night in Soho. The styling is absolutely wonderful, the cast was great and the plot, though not particularly surprising, kept me glued to my seat. Don't go in expecting a full-blown horror flick, the film isn't all that scary and tense really, it just oozes and bleeds atmosphere from start to finish. Edgar Wright did good with this one.
The World's End if by far my favorite entry in the trilogy (don't worry if you haven't seen the other two first by the way, they are only related by crew and a few running gags).