The X 4.6 RTR also has the Rotostart2 system. One thing to keep in mind, is that if you decide to go with the XL, and bolt in big power like a Picco .28 or the LRP .30, you'll be blowin' out your 3rd gear pretty often. Consult BudBud about this problem, as he has extensive knowledge about the issue. The clutch bell + alum. shoes, stronger steering servo (still not very good), steel spur, and receiver pack are all notable upgrades when comparing an X with an XL, but it comes at a premium of about $100 more. Is it worth it? That's up to you. If you sell off the XL engine, pipe, etc. you'll still need to add another $100-$150 to get a better engine and a good header/pipe combo. You may also want to put a 2 speed (another $50 or so) in it for durability issues. All in all, it's a close call and comes down to the handling characteristics that you would prefer. XL = more stable, easier to land the big jumps , X= easier to wheely at will, a bit lighter so a little more nimble. Both great trucks, tough as nails, can't go wrong on this one!