My first rig was a Glidecam X45/V25 arm combo. Also had a Gold Series arm at one point, and ended up with an EFP Blue Spring. The thing about the higher end Glidecams (in my experience) was that they are competent rigs. They are built relatively well, and they work like they're supposed to.
I liken it to comparing cars...your PRO/XCS/et al. is like a Bentley/Rolls Royce. Bespoke, high end, spare no expense. Real craft-work made by craftspeople for craftspeople. Steadicam would be like Mercedes AMG, BMW M-class cars. Proven, slick, does what you want it to, how you want it to, when you want it to, and still very high performance. Glidecam is like a Honda, or Toyota. It has just want you need, none of what you don't, and maybe missing some stuff you wish it had.
The X45 sled I had was like a fat V25. And oddly sized, but solid, aluminum 1.75" post (V-25 has a 1.5" i think), 3 HD-SDI inputs/outs, plus 4 (2-pin) lemos for power out, but strictly 12v. I believe it's the same with the V25. I liked it because the sled was short (in length..which is the way I preferred to run it) and it had plenty of video in and outs. You could get dynamic balance, as the battery hanger allowed fore and aft adjustments, as well as 180 degrees up or down for the battery mounts themselves. Top stage was solid, with x-y adjustments and fore/aft adjustments set with self-locking worm gears. The gimbal was pretty good. When I bought it, I had to re center it, but it was simple to do. Tedious, but simple. Seemed smooth in all axes, no major problems. The post had kipping levers for locks, which worked okay as "no-tools" locks. Sometimes, depending on payload, it was better to just use the hex driver to tighten everything down. There are index markings on the post, but no "mechanical" indexing..that is to say, the lower stage, once unlocked, can freely rotate around it's vertical axis, so that you have to manually set its orientation to the upper stage by feel, or by eye. At least I had to, because the printed markings on the post for orientation indexing didn't match. That's one thing that really bothered me. QC!
I believe that the V25 sled is similar.
The V-25 arm was like a...it's kind of like the EFP arm I had, but it didn't have the weight capacity or the build quality. It was, however, smooth, well-behaved, and light. It's a 3a design, though, so you get all the quirks of a 3a type arm. The other thing is that if it's a standard V25 you're looking at, Glidecam has a proprietary (which is to say non-standard) socket block and socket block adapter system...it's still 4 way adjustable, but you won't be able to use vests or mounts with industry standard sockets/adapters. Heaviest rig I flew was for broadcast...HPX2000 with an old NuComm TX...sled/camera was probably 40-45lbs, and that V25 arm seemed slightly over the limit.
The Glidecam V25 vest was...meh. It's competent. Very basic. All velcro straps. It works. Not a lot of support, or adjustments but it's light weight. No emergency release, if you need or want that kind of thing.
That's been my experience with Glidecams...hope this helps!