HN user
http://industrymailout.com is my vote. We use them quite a bit for numerous clients and haven't had any problems. Anything not present in their back end, they've built in. Anywhere from 1000 - 35000 mails without a hitch and an API.
just added my email address in there. i don't know if that means you'll be able to message me.
the company i work for isn't a startup. we do client work and we needed a reliable hosting recommendation for them.
on the side i run a small online magazine for arts and entertainment in vancouver. not exactly a startup, but we got high hopes.
i guess i didn't necessarily want shared. just something cheap for our clients. and since most of our clients are in vancouver, the hope was that it was close by so hops or latency or whatever were kept to a minimum.
no rails, mostly php and python. slicehost is looking really nice. anyone know where the data centers are?