I fish a lot for BIG gills with both my 8' St Croix Legend Ultra 3 wt & my 6'6" 2 wt (Forecast 2pc blank) that good buddy Joe Valencic built for me. At least in my rods, there is QUITE a difference. The 3 wt is a good deal "faster" & casts MUCH better in the wind, but BOTH are a hoot when a 9" to 11" gill or 2 lb bass is on the other end. As much fun as the 3 wt is, there is a MAJOR difference with that "softer" 2 wt when a big ol' honker is yankin' away! I also love fishing the 2 wt fishing for brookies in the Virginia mountain streams. The foliage blocks the wind well there, so it's really not an issue.
Build that 2 wt...you won't be sorry. Then give me a holler & I'll show you what REAL gills are, & they WILL test a 2 or 3 wt....here are a few examples...
The bottom picture is the 2 wt...the gill was 9" to 9 1/2"....the top pic is 11 1/4". Slightly longer & a LOT wider than the gill in pics 2 & 3. My buddy Gary told me I should also have had a "head on" pic of THAT monster.
Mike