What does a SLA really get you? It's just a method of apportioning blame *after* the damage is done.
Generally: it is a sign that the company has something to lose if its technical product performs badly. The proven track record of reliability is far more important than an SLA generally of course, but...
Specifically: it gets me one less thing higher-ups will moan about, because they want *all* parts of the project to be covered by some sort of SLA and explanations as to why an SLA doesn't really make that much difference on its own will likely fall on deaf ears and I don't have time to beat my head against that particular brick wall.
And to be frank, "apportioning blame after the fact" is no bad thing when it is not apportioned in my direction!
I recommend to you SimpleHelix. They stand behind their SLA. In the past they had some rough spots, but they always stood behind their products. Lately I have been noticing so many improvements and I credit them for that.