Not that rails doesn't scale but Dreamhost is known to disable accounts which use too much resources so I doubt you can run anything which will get any traffic...
I have a dreamhost acccount, but got another one at slicehost to be able to run my rails app. Has anybody tried to see what performance you can get now? My site doesn't generate any traffic yet, but it's ok to have a decent response time when I run a demo of it.
I completely agree, however subjective the determination of what one should get for their dollar is.
Having had a DH account for numerous years which I now use for nothing important whatsoever, I can tell you... you don't get much for your combo-meal monthly fee.
We're using it to power one of our demo servers, and it is very fast--definitely on par with mongrel and fastcgi. Stable too. We're not getting anything near production loads on that server, though.