I don't think Welch is that great and it's another hour north of the cities. Afton Alps is alright but I think it flattens out as much as Welch does if you're just going down the hill. The terrain park changes don't seem to be matching up to the "$10M in improvements" hype. There's a hot dog truck and a yurt now, though. Personally, I prefer Buck Hill.
As a MN native I think it's pretty easy to lose interest in snowboarding unless you get into the terrain park. It's just too flat. That said it's actually pretty good training for beginning terrain park because you can get in tons of runs and the obstacles aren't too big.