Not mixing apples and oranges with throwing other brands into the equation, Yes, I think the Gearwrench 90 tooth ratchets are better in some aspects than their 84 tooth series.
Now, I only own two Gearwrench 90 tooth comfort grip flex head ratchets in 1/4 & 3/8 drives and my observations are only based on about a month's use.
Visual differences: the comfort grip handle is now black and orange instead of red & black. it's shaped slightly different. the end of the comfort grip handle is tapered more and they've added rings or grooves towards the end of the handle to prevent your hand from slipping off. The 1/4 drive comfort grip handle lost the flat spot on the backside of the handle and is now round. the 3/8 drive model's handle is still flat on the backside. On the ratchet heads, Gearwrench added their new GW logo. Below that is a stamped 90T instead of the laser etched 84 tooth, and beneath the recessed direction switch, added four stamp lines or grooves. I don't know if these are cosmetic, to prevent accidental direction changing, or a new place for grease & grime to collect.
The ratchet head edges are radiused on the 90 tooth model similar to the 120xp but, the head remains as thin as the 60/84 tooth series.
The big differences between the 84 & 90 tooth versions is the pawl & drive gears. The gear cover plate on the 90 tooth ratchet is smaller than the 84 tooth and the gears themselves are supposed to be harder on the 90 tooth version. The drive gear is no longer flat on the back and has a small hole instead. I know you won't be able to swap a Matco repair kit into a 90 tooth ratchet. Not that you would want to but, some people did it with the 60 & 84 tooth ratchets for some unknown reason to me.
The only downside I've noticed about the 1/4 90 tooth flex head ratchet is that the ears or sides of the ratchet head don't hug the handle as closely as I think they should. there's a good 1/8 inch gap between the bottom edge of the ratchet head and the top of the handle. I think the gap should be next to nothing. Now, I own 60/84 tooth Gearwrench ratchets. I wouldn't consider upgrading to 90 teeth across the board because, I'm happy with what I have but, i did pick up the two 90 tooth flex heads because, at 8.25 inches long for the 1/4 inch flex head, and 13.5 inches long overall for the 3/8 flex head, they're my most used ratchets with thin heads. Besides, it's my understanding from speaking with the Gearwrench reps at SEMA last year, that the 90 tooth platform will eventually replace all of the 84 tooth versions just like, the 84 replaced the 60 tooth versions. Gearwrench really needs to offer a 3/8 drive in that 1/4 drive flex head body though.
