Kev Quirk thinks having a non-truncated RSS feed is a good idea. I agree. So does Zac Szewczyk:
Whenever I find a new writer, I go through everything they have ever written — turns out, good writers write good things often; this helps me find great works from their past. RSS feeds with, say, the site’s ten most recent posts make this much harder than ones with every article in them, so when I restarted this site, I took the latter route. Over a thousand posts would make my feed a hefty __ MB, though, so truncating the individual posts allowed me to strike a nice balance between the two.
Wait, how many people have their entire site’s archive available through the RSS feed? I’ve only ever seen sites with the most recent 20-40 articles at max.