For gameplay purposes, I believe that the rolls, sprint, jetpack, assassinations and new weapons are awesome.
Chronologically though... it really bugs me. These are Spartan-III's, which are weaker than Spartan-II's (John-117). Why can these Spartan-IIIs sprint, use jetpacks and roll while a Spartan-II with Mark VI (these Spartan-IIIs have Mark V!) armour can't do all of this?
Another thing that bugs me: Spartan-II's supposedly have enhanced vision to the point of night-vision. Why do they need flashlights? Why do ODST have the VISR but MJOLNIR Mark VI doesn't?
Did I mention that the Mark V armour that the guys on Reach have includes an ELLIPTICAL RADAR? Three dimensions, show a sphere around you.
I'd personally use a needle rifle than a Needler and Covenant Carbine separately. Wouldn't you like the possibility of taking headshots or exploding the enemy with one single rifle? Only difference is that the needles don't track. So what (unless the needles of the needle gun are slow...)?
I'm just gonna be having this feeling throughout playing Halo: Reach of "Shouldn't the guy who saved the galaxy from the Flood and Covenant Loyalists have this?"