The question is, do you routinely break strings? And if so, after how many matches/hours? What surface do you normally play on (e.g., indoor hard, outdoor clay, etc.), and at what level?
I use 17g gut mains, 17g poly crosses (currently Klip Legend & MSV Co. Focus) for outdoor hard & indoor hard, but will switch to 16L or Pacific Tough Gut during clay season as clay will eat the gut up after 5-6 hours of play.
Tension is obviously a personal thing, and as I've found out recently, numbers are irrelevant because it all depends on the stringer & the machine (in other words, one person's 52 can be another's 55). I just would not go too low w/ the gut as the ball will tend to fly below a certain tension. You just need to find what that tension is...
Also, I'd stay away from twisted polys as crosses. They will tend to saw through the gut and impeded the 'snap back' effect people talk about here. Personally, I didn't like ALU Rough (found it too stiff), but that doesn't mean it is bad, just not for me.
"Nobody beats Vitas Gerulaitis 17 times in a row" -- Vitas Gerulaitis, after beating Jimmy Connors on his 17th try.