KLIM Latitude has been my go to three season jacket for the past three seasons. I bought it on the BMW MOA site from someone upgrading. It was like new-not sure it was every outside! It has great vents, padding, and the large fits me ok. I'm 5'10" and average build at 175. I can add a thin base layer, my heated vest and another shirt and still fit. Medium would be too snug for any layers. My only complaint is the fading in the hi-vis material. My wife's Tourmaster is the same vintage, and yet her jacket is still bright and almost new looking. I'm not sure I won't look there (and lots cheaper) for when this jacket needs replacing. I've got almost 120K on it, so it doesn't owe me much.