Size not considered, I fired up my old UK Reisse Arbiter England Fuzzface and it sounded fantastic. It's just huge, warm, and totally oldschool. The Octafuzz it a little brighter, "spittier", and has way more fuzz on tap. Also, if you are into fuzz but can't seem to get them to work for you check out the Fulltone Catalyst. It's affordable, VERY compact (about the size of an OCD), extremely tweakable, and good sounding. It can act as a decent overdrive/clean boost on the "Spark" setting and full blown fuzz on the "Flame". Be warned though, it's a little raspy when used in front of a super clean amp. It sounds stellar through a dirty amp though!
'67 and '74 Fender Twin Reverbs, '74 Marshall 1987 lead mkII, Metro Superlead 100. Pedals from TC Electronic, Ibanez, Dunlop, BK Butler, Electro-Harmonix, Fulltone, Maestro/Gibson, Loopmaster switching, VoodooLab, Boss. Gibson and Fender guitars, Dimarzio pickups.