Is that good when a company (quillhost) offers 95% uptime SLA?
Is that an average rating?

Guess that uptime SLA from quillhost is average.
That's quite normal.
What service do you want to use from them?
I have heard their VPS deals are good.

Want to mention that quillhost company provides a wide range of hosting services which cost little comparing to the offers from the other companies.
There are many specials on their web site too which can be used too have resourceful deals at lower rates.

You know, I would better trust time-tested companies that offer 99.9% or 100% network uptime.
I am happy dealing with Bodhost.com - I have been using their dedicated server hosting services for 5 months and very glad to deal with this company. Their support is friendly and responsive. They provide great network uptime (100%), so my web sites are always up.
If you are interested in reliable services, this company can be a perfect option.

Quillhost provides a lot of other resources and featured in their plans which cost little but resourceful.
At the OP, have you already signed up with them?