Oh, there's no doubt that Kanto was better in HGSS than in GSC, but I just dislike the whole concept of returning to a region with your already powerful team and simply strolling through it. GSC was ruined by the inclusion of Kanto, unfortunately; low levels in Johto, and a hollow Kanto.
Kanto was structured perfectly in RBGY, and had the real sense of a journey travelling across the land. HGSS still ensured that this was lost, and no amount of returned Viridian Forests is going to change that.
This is why I cringe every single time someone says that a game should be made with all the regions in it; the levels and the sense of progression would be awful. If they do include more than one region, they should put a quarantine system in or something, so you basically have to build a team for the new region, with the ability to swap after beating that region's league.