I got a pair last year and have about 1,700 miles of riding on them. I tried on pants in the $600 range from several very reputable gear manufacturers before deciding to go with the Stealth bib. Many were from the ski industry, which quite frankly has much better technical gear available than what's marketed to sledders. I feel Klim is really leading the sled market as far as overall quality of their gear, I'm not saying the line is flawless, but it's a pretty solid product overall using quality, proven, brand-name materials.
Pros:
-VERY high quality pant overall, on par with the nicest ski touring and climbing pants available and tailored to the demands of sledding. Much more durable and abrasion resistant than many of the ski/climb pants.
-Nice mix of fabrics. 4-way Gore-TEx stretch fabric in the crotch area is awesome, the pants never felt like they were impeding my movement in any way. Durable fabric on the inner cuffs that gets worked against your tunnel.
-Very light weight pant. I mean that both figuratively and literally. It weighs very little and has zero insulation value. I run hotter than hell so this was great for me, I wore a mid-weight base layer and was pretty much perfect most days and could use the vents if I got really hot.
-High back on bibs, I never got snow down the backside. Also, the upper bib section is stretch fabric so it moves with you nicely.
-The knee pads that are built into the pants (removable) are D30 material, which is a flexible rate sensitive material-it's soft until you hit something, then it becomes really hard. The knee pads I always wore under my pants from mountain biking with the same material are $130. I don't have to wear those anymore and it's much more comfortable having it built into the pants.
-There is a lace hook on the gaiter. All pants should have that.
-The zipper around the bib didn't make sense to me for a while. Then I realized I could use a crapper without taking off my jacket. Genius.
-My a$$ never got wet in these pants. No matter how wet my seat was, my a$$ was dry. Having a wet a$$ on a cold day sucks. We can all agree on that.
Cons:
-The gaiter diameter was a bit too loose on my boots which would allow snow to creep up under the gaiter and into my boot on deep days. I used some rubber ski straps around the outside of the gaiter cuff to keep them in place. If you have big diameter boots, this probably won't be a problem. However, for me it was. The best gaiter design I found in my search was, by far, the one on the Patagonia Super Alpine Pant ($549). Put on something like this and it'd be sweet. It's Hazmat suit sealed:
-Another issue on the gaiter, the material is the same as the bib portion, and while it won't let snow though, it does get soggy. I'd love to see some other material used here.
-The fit is 'athletic' but will favor the skinnier overall guy. I'm 6', 190 lbs. Not tiny, but not huge. I have thick thighs, skinny jeans are not my thing. By all measurements on the Klim sizing chart, I'm a 'large', but in reality the large size is pretty much skin tight on my thighs and waist, but the right length. I went with the XL size due to this, so if you're on the edge, go up, not down. However, this made the knee pads sit about an inch lower than I'd like, I have a lot of extra shoulder strap, and a bit more room around the waist than I need.
-They are not indestructible. Nothing is, but compared to the moto style pants, they are going to be more prone to damage. I do have 3 small tears that will have to be patched before the season, the largest being about 1 cm.
Final Say: Not perfect, but still the closest thing I can find to my ideal pant.