I used Dominants on my viola while in high school because the director insisted upon it. However, I always had issues with the A string unraveling near the top of the fingerboard. This could have very well been because I was young and terrible at keeping the instrument wiped down after playing. 🙂
I started trying out Pirastro Tonicas, which are very good, warm strings. They also break in and settle much more quickly than Dominants. I haven’t used them for a little while now, but from what I understand they’ve reformulated the strings and they’re now a bit brighter and more neautral-sounding. Probably good for an instrument that’s less naturally resonant.
I’ve also used D’addario Helicores, which are fantastic steel core strings, and much warmer than that type of string typically is. They’re very affordable too, which is always a bonus.:-)
As for E-strings, I’m still on a bit of a hunt for the best match with my instrument. I’ve used Dominant (which is TERRIBLE) and it’s fairly gritty and stiff-feeling. Right now I’m trying out Warchal’s special spiral E. It’s great at reducing the whistling tendency of E strings and has some really interesting harmonic vibrations while playing. It’s fairly brilliant, which isn’t necessarily the best match for my lively instrument. I have four more strings coming in later this week to try out – Goldbrokat, Pirastro Gold Label, Hill Medium Guage, and Kaplan Solutions Wound E-string.