Nope. Feel free to review the TOS (there’s a link on the main website) as it doesn’t state any SLA. I’m unaware of any “regular basis” downtime either. I’m not sure if it’s an issue of complete impatience or, possibly combined with that, complete “newness” to shared hosting and/or non-SLA providers.
I’ve not had any major downtime on my sites to complain, and when I do file tickets, they are answered and worked on quite quickly.
You might also consider the fact that DreamHost has hundreds if not thousands of servers, issues are to be expected almost daily from one server or another in that regard.
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