I have to agree with the rest, go with what you're the most comfortable using! I use different items depending on how I intend to fish, and don't really limit it to just fly fishing. I have no issues with wearing a vest & carrying a spinning rod!
I had an Orvis Tak L Pac vest many years ago, and it was OK, but was a bit warm in the summer months. I have a chest pack, and a couple of fanny packs, and 2 other vests I've since purchased. Not a big fan of the chest pack, but it just may be this particular one. I would have to go dig it out of the closet to see who made it!
One vest is a cheap Pflueger I bought from an Ebay seller, I think I paid about $15 for it. I actually like wearing it, it's light weight, although there's not enough pockets, but it does cause me to NOT carry more than I need. Not as well made as the Orvis, and with a lot of use, likely won't last but a few years, but for me it's plenty comfortable. The other vest was a gift, and is a shorty style, and has a green camo leaf pattern on it. It's fine, but also a bit warm for summer fishing. Again, not sure who made it!
One of the fanny packs I got for hunting, and I like it for carrying small amounts of gear. It's made by Hunter Specialties. Nice camo pattern on it too!
The other was also a gift, and I don't think I've even used it!
One of the best things I've found for carrying gear is an old military surplus, canvas gas mask bag. I have 2 of them also. They have an adjustable strap that fits very well across my shoulder, and another strap that secures the bag to my waist. The bag stays right under my left arm, down near my hip and is not especially cumbersome as long as I don't cram too much gear in it! Holds a couple of medium size Plano boxes, or smaller fly boxes and all the gear I really need. I had one many years ago and used it for small game hunting & carrying fishing gear. I liked the simplicity of it, and it was very durable!
I had a house fire many years ago, I lost the Orvis vest, the old gas mask bag and some other things, so have not been inclined to replace such items with products that are on the high end of the cost scale! Frankly, I've actually liked some of the "cheaper" products better anyway!