Other great resources are www.lowendmac.com and www.mac512.com
Low End Mac have links from where you can download Mac OS 7.5.3 (Apple are still charging for 7.6.x)
I used an LC475 for a couple of weeks back in 1995 - not too sluggish from what I remember (although I was used to my STE and the Mac Classic), slightly zippier than my PB165C I'd say (it didn't take half a day to load MS-Word, for example)