Not sure what the difference is between the ht1 and ht2 apart from i was told that the wheelbase is shorter on the 1 and that because of this the 2 handles much better and i am pretty sure that most parts on the 1 can be upgraded.
That said with an oddified engine and tonegawa servo it has obviously had some money spent on it so may well have other upgrades already.
I have just bought an ht2 as my first largescale and the quality is stunning, i certainly wouldnt pay the new price for them but was happy with the price i did pay. I only took it out for the first time yesterday for a quick run on a football field just to see how well it runs and it was pretty quick and handled superbly, it was so easy to drift it and no matter what i did there was absolutely no grip roll, just cant wait to get it on a proper track now.
It is now awaiting repairs as both of the rear wheel bearings on the n/s/r collapsed and stopped play so i am glad i took it out for a test as i would have been gutted if that had happened in a race so both sides will now be replaced.