Silent Spinners are good for Dwarfs, but are often too small for larger show Syrians. We find that the larger hams have to arch their backs when on Silent Spinners, which means they are too small for them. We think Wodent Wheels are a good size, and even the largest Syrian we have had could run comfortably on one.
If your hamster howevever seems happy with a Spinner and isn't arching his back then perhaps it would be a good idea to keep him on this. We find that some hamsters don't like the Wodent Wheel-type wheel with the entrance holes whilst others won't use the Spinner-type!