If you do go with the Savage 4.6 X go with the RTR version and not the kit. The kit comes with the K4.6 motor and the RTR comes with the F4.6. The F has a lot more power and is a pretty nice motor for a factory ride. You will be happier with the F. If you go with the XL I would pull the motor before ever running it. They seem to be getting good money on ebay and would be something I would first dump and replace than deal with. The Aftershock/LST/LST2 route is a good one to go. I would wait on buying one NIB until the XXL is out to all the stores. I would think the rest would all drop in price when the XXL actually hits the market. The LST2 is hard to find right now though. Losi may have stopped production and may be discontinuing it with the XXL release. The great thing about the aftershock is the ability to upgrade to LST2 spec. The LST/LST2 have great radios with them. They are JR XS3 synthesized FM. They may not be 2.4 but they are darn good for a RTR radio.

As for size in general it all depends. I know transportation is tough but go to the local store and size everything up. Ask yourself if the extra size is worth the extra money. To some it is, to others it isn't. Figure out what the local shop sells and what they sell parts for. I would tend to pick a model the local guy at least carries parts for. Once you have it narrowed down to a specific brand read up on the specific differences between the size differences. Is getting bigger worth potentially handling worse? Does the bigger truck have enough power to move it how you want? Does the bigger truck do anything that the smaller one couldn't in your driving use? It all depends on the brand. What do you want? It doesn't matter much what we think, only what size truck you think will make you happiest.