Rosco, the heavier draw weight can make a big difference as you are seeing. Flatter trajectory, cleaner release. That will usually make you a happy archer. Unfortunately i am stuck with lower draw weights due to injuries, but i have played with them enough to know. I would love to shoot the 55+# bows. It makes a big difference if you can handle it.
That said, I have never shot a string follow ANY better than a backset or straight. I think partly it may be due to a little quicker arrow and thus, flatter trajectory when there's backset. I have a couple SF that I really like, but I think it's the overall design, not so much the SF.
Don't give up on a well designed backset bow like the one you have in the same weight. You may end up with 2 favorites!