Have a chance to buy one of these at a pretty significant discount from a member at my lease. What's the OB's opinion? My main concern is the sliding (horizontal) windows…are they insect and rain proof? Tia.

90% of your rain problems are solved by proper overhangs. I build my own blinds with metal roofing and at least a full 12-14" overhang. I've Never had one leak and mine are literally hinged plywood boards that close into a recess. Since your window is commercially made and probably at least 400 times better, I'd say you aren't going to have issues. Bugs? I dunno…never seen a blind that didn't have some level of bugs but I don't know what their manner of ingress would be. Wouldn't think the window, though.

The types of blinds you are talking about are made in all sorts of ways by all sorts of builders and they are all generally pretty tightly built from what I've seen. I'll let others that have particular knowledge chime in though.

They are very nice blinds. I too don't particularly like the windows they use; I think they are a cheap letdown from an otherwise high quality blind, and I dislike horizontally sliding windows on a deer blind in general, and dislike windows without framing around each pane. On the other hand, I love pretty much everything else about those blinds, especially the amount of shelving, the shelves up high under the roof pitch, the steep pitched roofs, and the roomy sizes.