Frank, looks like you're having the same epiphany I had over the last year. I got my first 4x5 rig about 11 months ago. At first I didn't have an enlarger that size so I made contact prints on regular enlarging paper. WOW!
One thing led to another. I got an 8x10 and some Azo just about a month ago. I don't think I'll ever go back. The 8x10 Deardorff is the sweetest camera I've ever worked with. Contact printing with Azo and Amidol is every bit as easy as Maichael A. Smith says it is.
The 4x5 and a spare 35mm are going up for auction right after the holidays. My only regret is that I didn't start using 8x10 a long, long time ago.