I concur with above posters. In short, if you prefer club lounge upgrade/accesses, go with Hyatt; if you prefer suite upgrades, go with Starwood.
Hyatt lounges are more common and better, however, I have never gotten a suite with Hyatt without using points or coupons. You are lucky that you've gotten suites from Hyatt from time to time, as your post seems to imply. I've been Hyatt Diamond for years and SPG Platinum since inception. Oh yes, I qualified for both with stays, never comped.