How do these engines match up to the RB V12 engines? They're close, price wise, but just curious about the performance between the two? An RB V12 goes for 220 (3 port) where the 5 port version is 249. These prices are from acehardware. I want another engine for my other MTX3, and was considering the OS12 TZ, but if the RB is only 50 bucks more (5 port) and performance & reliability is better, it'd be better to go with the RB.