steve- As AI said it is old and a little weaker than the MT12 because it doesn't rev as hard. With crisp driving skill you may be able to get away with it on most small tracks and in a beginner class. I'm running that engine now with a THS pipe, byrons 30%, and an OS R5 plug. This engine stays running constantly and puts out pretty good power. Everyone says go with the most power, but can you control it on a track? Most tracks are very technical and small...so there is no need to spend $$ on a $300 engine. This engine will be for practicing and such, but since I am running on a much larger track I have another engine on hand.
JS- KO gave or JR bought the design from KO. It's not an upgrade or evolvment from the R1. The Z-1 is very similiar to the KO radio...just different color here n there and the KO has mostly KO logos. It's really easy to use especially when you can hop to the menu settings via scroll buttom or +/- button. It's not like the 3pk where you have to press all sorts of buttons to get to one setting. Heck the dial button will scroll as fast as you turn it! The Z-1 does have the synthesized module for it and it works great if you don't want to get spektrum. If you are interested I have a spare Synth module for the Z1 in MINT condition I can let go for $50. It's regular price is $90+.