Well The RCM "kit" is excellent. Converting a nitro is simple. The hardest part actually is drilling a few holes through the chassis to mount the batt. tray. Mikes parts are top notch. You can even get a custom battery made to your specific dimensions if you so choose. I have 5 custom trays Mike made me for each vehicle's specific batts and they are perfect.
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S
Best kit is the tekno.. if you don't do that kit the RCM mount is nice but I'd still stick w/ the losi battery tray and conversion parts. Even the losi motor mount is pretty decent, but I like Mikes just a touch better.
The tekno kit has a MUCH improved COG as well as easy setup for mechanical brakes, so you can tweak the bias.