Negotiation is one of the The Donald's strong points. Not only does he have backbone, but he is a businessman. Therefore, I believe he would get the better end of the deal with Putin—at least better than President Obama.
Well, I hate to say it, but Trump would likely do a better job. As said by Kilk1, Trump probably does have more of a backbone, because Obama has conceded to popular consensus an the Republicans way too much for me to believe he ever had a backbone. As with negotiation skills, there are two ways to make a negotiation go your way: either scare the hell out of the other guy or outsmart him, and neither Trump nor Obama are exactly razor sharp, but Trump is at least far more frightening: if I was Putin and Trump was the American president, I'd think of him as a rabid, retarded gorilla with a bad toupee who happens to have command of the largest, most expensive and destructive military in the world. I'd think of Obama as a pushover because he probably is.
Trump is incompetent. There's no way he can handle the pressure that's on the White House.