Mountain Buggy are very good indeed. Works well on most surfaces, even hilly offroad.
Less good, but still easy enough (on the flat, t least) we had the running chassis addon for the the Bugaboo Bee Plus. Pricey, but we sold it for £20 less than we bought it for 5 years on.
Out n About. Relatively cheap on Amazon I think. Lots of friends and family got them too. I ran 100s of miles with ours and used as a robust off road pushchair
Running prams
Anyone used one with success?