Good choice on the 457. I bought the Ruger RPR for my son so that it's adjustable for him, my daughter, and I (if I feel like it) in seconds. The accuracy can be decent with certain ammo (CCI mini mags appear to be best in mine). But I haven't been able to shoot a 5 shot group at 100 yards under an inch.
My CZ's (452, 455, 457, 512), on the other hand, are clearly more accurate. I haven't shot all of them at 100 yards yet but the 455 and 457 are capable of shooting under an inch at 100 yards with reasonably priced ammo (under $10 a box). Pretty much everything is better than the Ruger other than adjustability.
I would have dumped the Ruger if it weren't for my kids being 6 and 9.