I love the rack format and have moved through a lot of cheaper units:
DEP-5, SRV-2000, Quadraverb, Midiverb, Line 6 Echo Pro, and plenty more compressors and eq's etc as well as some Akai samplers.
TheY are all pretty decent, the roland's are a little noisy but I was able to get the best deteriorated VHS simulated sounds I've ever gotten with the DEP-5, atleast on guitar. I'd like to get another quadraverb, but it's better for electronic stuff the guitar imo.
I've enjoyed more than a few 19" synths as well: JV-880, FB-01, still have a TX81z.
It was piling up and I was having issues with small rack setups everywhere so I've tried limiting myself to my 24u rack and sold off all the excess.
My rack now consists of:
Eventide Orville
Eventide Eclipse
Kush Tweaker x2
Kush Electra
Motu 828es
Alesis Adat expander
Tx81z
Samson s-patch x2