I've got the Performance Illuminte Commuter jacket, and it's amazingly warm and versatile except for the sleeves. They need to be vented, but aren't, both the upper back and underarms have vents that allow for plenty of air to flow in those areas. Removable sleeves seem like a good idea to me, but I can't tell you how those work. Most of the jackets with removable sleeves have the sleeves connected, and that would mean removing a backpack to remove the sleeves if you use a backpack like I do.