I am very fond of Aerostich suits, I got my first Roadcrafter used around '98, bought a new Roadcrafter around 2004 and a new R3 in 2015. I commute almost every workday, almost year round (northern Europe). I use a 42S in the Roadcrafter (black/grey), the R3 is black/black with reflexes and also 42S. I am around 5'7", #170 and 31" inseam. I always use a hard shell Dainese backprotector which takes up some room - if you use a backprotector it is very important to clarify this while ordering.
As I ride all year I prefer a loose fit so I can layer up during winter and also have the suit ventilate better during summer, mind that I usually ride in generally lower temperatures (a max of around 80F, lowest so far is 10F) for a 20 mile commute. So, the idea was to get the R3 for summer use, but as the Roadcrafter now has defective zippers and isn't very waterproof, I am using the R3 in colder temperatures. Comparing the two, I do not like the R3 - it has some different design features and I do not think the workmanship is on par with the 2004 Roadcrafter. I much prefer the lining of the Roadcrafter, as it is much easier to get the suit on and off, and the design of the R3 with the glued on velcro tabs, have worn away the unprotected Goretex membrane and the welded tape seams are not correctly done (too short and too exposed) in the crotch area, so now the R3 leaks quickly in the upper arm area, shoulder and crotch.
I shall probably get a new Roadcrafter Classic soon, as I do like the idea and have been using this kind of suit almost daily in 20 years - but I do not recommend the R3.