The easy and most obvious and probably accurate answer is "It's way too early to tell".
Titans Return appears to be much like Combiner Wars, as in they are new versions of Gen 1 characters. In that respect Combiner Wars deserves a lot of credit.
Combiner Wars can be credited with the following:
*Giving us new Generations-styled figures of G1 toys that hadn't gotten one yet (Huffer, Sky Lynx, Bombshell etc)
*Giving us Gen 1 inspired Combiner teams (Stunticons, Aerielbots, Protectobots, Constructicons, Combaticons)
*Giving us versions of G1 characters that had already had the CHUG treatment that now combine. I have a few new versions of Hot Spot (GDO, Titanium etc) but none of them combine to form Defensor.
*Giving a chance for people who missed out on previous CHUG figures of classic characters to grab them. For the most part they are inferior to the CHUG versions (Prowl, Sunstreaker, Hound, Cyclonus, Drag Strip etc) but it's a good second chance for many.
*Even more multiverse versions of classic characters. I personally love to get many different versions of G1 characters for my displays.
*GESTALTS! I'm loving all of them but frag Devastator rocks! It seems (amongst my mates anyway) that after Optimus and Soundwave that the third robot they can usually remember is Devastator.
Titans Return
*A lot of the character revealed thus far have already had the CHUG treatment (Nightbeat, Blaster, Rewind, Hardhead, Galvatron etc) so it depends it you feel they needed better versions. I'm looking forward to having a Blaster that turns into a Ghetto Blaster, though I was pretty happy with my FOC version with his little warriors that you could eject. It remains to be seen if the Titans Return figures will be better or worse than those that came before. A lot of them do look like they will be an improvement, though many question the inclusion of a Headmaster gimmick on what were previously non-headmaster characters.
*There are a few characters coming out that haven't had the CHUG treatment yet that I am looking forward to (Skullcruncher, Horri-Bull, Fortress Maximus etc). The more the merrier I say!
So while a lot of the CW figures were simplistic and there was a lot of mold-sharing, the CW line has been brilliant as a whole. I hope that Titans Return can prove to be even better, but they will have to pull out all the stops to do so in my opinion. But at this early stage, as I said at the top of this post, it is just way too early to tell. I certainly can't say without ever having touched a Titans Return figure which I prefer.