I ended up watching the newer of the two films first, not sure if that would make a difference or not but I thought it'd be worth pointing out. Two of the more apparent differences I noticed in the films were:
1, the newer film had a much more showcasey feel to it and 2, the older film had a much more military and family oriented feel to it. To my first point on the newer film having a "showcasey" feel to it, it seemed as if all the actors were in the spotlight. They all are in dramatic lighting as if being shown off at a dealership which fit the feel of the movie well since they're pulling off a grand heist in an elegant fashion. I wasn't able to catch this in the older version, maybe I wasn't paying close enough attention or it wasn't as apparent but I much preferred the newer version because of this since I believe it added to the movie.
And secondly, the older version had a lot of military and family oriented influences on it. A number of times the fact that two characters were from "X" platoon or from the same squad and they wanted to get their crew back together was used as a bargaining point. And more to the family side of things when Richard Conte met his son after "being in Japan" (while he was actually in prison) it seemed very similar to a father coming back from being stationed overseas and seeing his child for the first time. Or when Joey Bishop (I think that's the right actor) called his mother for money and she mentioned that she had been home for 3 days and he had still yet to call, is just another example of what I believe was an overabundance or just far too blatant use of "family values" or something like that. I think this is all just more a sign of the times than anything else and it didn't necessarily take away from the movie for me, just very apparent. Lastly, what was up with Don Cheadle's accent in the newer film? I was so glad Sammy Davis Jr. didn't have anything like that in the older version.