I loved our Bee Plus. Nice and light and can fit down the aisle of buses here so I didn't have to get on at the back like many people with prams. The kids always seemed very happy in there and it was SO easy to push and steer, unlike others I tried.
I'd definitely say it's well worth it. We had a Mamas and Papas pram first, I think it was £350 but when I didn't like it we sold it and could only get £50-ish even though it had been used a few times a week for less than 6 months and was in perfect condition. The Bee has been used pretty much every day for three years (2 kids) and I'd still expect to get a few hundred for it. So it's a bigger upfront cost but it's retained value much better AND was a much nicer pram to use.
I've never had a problem with the wheels. Well, if you run really fast with it they can wobble a bit, but it's not a sports pram so I think that's fair enough.
It is okay on grass, cobbles, through 2 inches of snow, gravel that is fairly firm. I wouldn't use it on a hike though.
We used it with a Lascal buggy board and even with a 4 year old on the board, the whole thing was still easier to push than other prams I tried with one child in them.