I'll give my opinion - I haul my tractors very frequently (several times a week). I'm running a Big Tex 14GN gooseneck trailer, 25 feet + 5 feet dovetail. I've already got a lot of miles on it and it has held up very well. Is it the nicest, best built trailer in the industry? No, but it is built well enough. It uses pierced-beam design, whereas some other trailer makers (Gatormade, Kaufman, others...) use channel cross members welded on top of the I-beams. It comes standard with LED lights and a spare tire; mine has the "mega ramps" which are full width, spring-assisted, fold flat or stand up, with self-clean dove. But I'm hauling much larger and heavier tractors than you.
There are a couple of youtube channels made by "hot shot" truckers...guys pulling goosenecks with 1-ton trucks for a living...that are running Big Tex 14GN trailers. Traveling all over the country, roughly 60,000 miles a year...and these trailers are holding up fine. Everyone has a bad experience with a brand, be it car, truck, trailer, or electronics device...but that isn't indicative of the brand as a whole, necessarily.
Kaufman trailers can be fine. They are at the cheaper end of the spectrum so people look at them. However, they are cheap because they don't include a lot of the things other manufacturers include standard. Notice the one front jack leg instead of two. No torque tube, the lights, the ramps, the thinner beams, etc. Yes, you can option for all these things and have as good a trailer as the others, but it no longer is cheaper. Some people make do with the base trailer or just a couple of options.
Don't worry about fuel economy. It's not going to be good no matter if your ramps are up or down.
Your tractor, without any rear attachments, you fit on a single-axle bumper pull trailer. Proposing a gooseneck for a B2650 is way overkill. A gooseneck does have some handling and maneuverability advantages compared to a bumper pull, plus as someone said fewer people will be able to borrow it. Is your truck already equipped with a gooseneck hitch? If not, it will cost you a chunk of money to have someone cut holes in your bed, install the under-bed hitch, and set up the wiring into the harness / plug. Keep in mind a gooseneck trailer is much more of a pain in the neck to hook up to - if you don't have a bed camera you'll probably need to make a few attempts to get things lined up right. You'll have to get in the bed to attach the chains and lock the coupler and connect the breakaway. You also need to stop and open the tailgate before backing under the hitch, and leave the gate down when you disconnect...pull forward...and then close the gate. A few pickups have remote-release gates, but very few. Finally, a gooseneck trailer weighs more empty than a comparable bumper pull, meaning you are burning quite a bit more fuel (a lot more than just having tall ramps) even while empty.
The type of trailer you showed you are interested in seems to have basically zero need or advantage to being a GN. It won't have any more GVWR than a bumper pull, but you'll have a heavier trailer so less actual payload. Plus, this is not a deckover design, meaning you can't load from the sides with a forklift. And 18-20 feet is the bare minimum to get a vehicle on the deck, but you can't overhang the front because of the GN structure being in the way. Basically no room to properly chain it down.
For your current setup, I'd buy a high quality landscape-style tandem axle trailer, with dual 5000lb axles with brakes. Your GVWR would be 10k and your payload would be 7500lbs. This type of trailer can easily handle be on the road all the time, and with 7500+lbs payload capacity gives you 3000+ lbs of payload beyond your tractor, loader, and mower. I'd get a 20'. Rotary cutters take up a lot of space.
As for brand, I've had excellent luck with Cam Superline, PJ, and Big Tex.