Update....
Had some blind tastings tonight with me and my brother....
Here's the samples.
We both agreed that the greenbelt had more "bitterness" than the WLP001 sample. The WLP001 sample has a little more "complexity" - don't really know how to describe it....
Greenbelt seems to be a little "cleaner" - meaning, more crisp.
The aroma seemed similar between the two.
Overall - I was surprised how "different" the two beers were, considering they were derived from the same wort and what I thought would be similar yeasts.
WLP001 = more mouthfeel, less bitterness (relative)
Greenbelt = crisper/dryer, more bitterness (relative)
Either way - both beers were great, and I look forward to making an IPA out of greenbelt since it seems to enhance bitterness and make for a perceived crispness.