The TakaraTOMY version definitely looks nicer, and of course, Scrapper has better elbow articulation as a robot. But drawbacks are:
* Later release; December 2015 (so some may arrive as late as January 2016)
* More expensive. Pre-orders are at around $240 before shipping; so when you factor in shipping, it does make the toy substantially more expensive than getting a local Hasbro version. Although another advantage with pre-ordering the TakTOM version is that you don't have to go through all the trouble of finding a local Hasbro version.

So yeah, both options have their pros and cons, it all depends on what you think is worth it to you.

If you've already pre-ordered the Hasbro one, then your options are:
* Cancel the Hasbro pre-order (if you can) if you choose to get the TakaraTOMY one
* Get both and sell one
* Keep both and display alternatively as Handsprime has suggested