I'm a little late to this conversation, but for insulated hub shelters I have an Eskimo 9416i which is the same size as your Frabill but insulated, an Otter Vortex Lodge hub which is the typical 9X9 square, and the bigger Otter Vortex Resort hub you saw us camping in last weekend. If you find your 450 too small, let me know and I'll sell you my twice used 9416i cheap cheap...I was going to offer it too you when we were up but wanted to make sure I was coming back in March first.
Insulated is the only way to go. It's also not a bad idea to get the size that's just big enough for your needs as they are quite a bit heavier than non-insulated tents. I think you'll like the 450XD for day trips. A gray interior is the way to go IMO, although lots of people prefer black. The ultimate hub shelter *should* be released next year...the Otter Vortex Pro Resort Thermal Hub. It's the same as what we had set up but with a walk out door. I'm just hoping it's six sides plus the door...they don't decrease space using one of the six sides for the door like Eskimo.