I would lean towards a 5 Wt if I was going after bigger trout especially in larger rivers or fast moving water, but that is subjective, a 4 wt will get it done too.
I have a Avid 3 wt that casts like similar to your 5 wt I don't like it much either, subsequently I don't use it much.
I would have a look at a few Sage rods as well to get a comparison. It sounds as if you may prefer a softer rod as opposed to a fast action rod. ( but I may be reading that wrong) Try a Sage VT2 or a SLT in addition to the other Rods you have listed if you can. Try to use the same line on all of them. Sometimes a line change can make a decided difference in the way a rod casts.
The Orvis Zero-G's and T-3 rods have a few different Flex ratings, mid flex being a little slower or softer than the fast action tip flex rods. Try both kinds and see if one suits you better.
I have no experience with Scott or Winston Rods. But I hear good things about both form people who fish them.
The high end rods and their aluminum tubes are nice( I know I own several), but the ones that come in a nylon tube are just as capable of catching fish. don't overlook a lower price rod in your quest to find that perfect rod. You may be surprised in what you find at the mid range of the price scale. My favorite trout rod is a Sage DS-2 8'6" five wt. It was not real expensive & with the right line is a real performer.