I'm in London, and I'd say it's a small step backwards. The points of interest from Yelp appear to be consistently off by about 10 metres, and many points of interest are missing altogether. I do like the way you can click on a point of interest, which is something you couldn't do in the old Maps app.
So far, all the addresses I've tried are correct, and the driving directions and speech recognition are a step forward. The tube/bus directions from Google were always inaccurate, so I was already using a dedicated app.
Yelp's points of interest are frequently at the wrong location. I've noticed this using Yelp's native app, which displays things on Google maps, ironically (ironically because Google knows the correct location if you search for the same place by name; I heard that Yelp stores lat/long for each place instead of letting Google look it up by name).
In my experience, this problem with Yelp's data is worse in Europe than the USA.
So far, all the addresses I've tried are correct, and the driving directions and speech recognition are a step forward. The tube/bus directions from Google were always inaccurate, so I was already using a dedicated app.