It's not quite the same. There are a ton of little differences, and a few major ones. The castle can't be destroyed with OP weapons other than bombs, the wind obstacles and gravity pads seem a lot stronger, which significantly changes some of the challenges I liked to do. Plus, I just liked coming up with tricks and challenges using authentic, original sandbox from the developers, rather than a close-but-not-quite replica. And I liked the convenience of not having to mess with Multiverse to get it.
Finally - this is perhaps the important point - I see no advantage whatsoever in taking away something that the developers already went to the trouble to design.
Tolbrynd has a distinctive appeal and adds variety, IMO, but I still prefer the Ipsilon look as well. Based on the developers deleting the old sandbox, and automatically putting Tolbrynd textures that you can't delete on the hills and basic shapes, I get the impression that they're trying to distance themselves from the simplistic style of the original game. I think this is quite a mistake! The minimalist style, while simple, has a distinctive charm to it. Plus, it's what the whole game looked like when it got so popular in the first place.