I’ve a short sleeve too. I don’t think I’d buy a long sleeve. Firstly, it works so perfectly to pair with different grades of arm warmer (or not) depending on the conditions it would be wrong to lose the option. Secondly, if it’s the sort of conditions where I’d want the long sleeves over arm warmers, I’ll probably want a proper jacket or some layering.
13thfloormonk makes an interesting point. I expected it to be versatile. I’m not sure it is, really- you can’t really layer with it, mine at least is a bit warm to layer over and a bit tight to layer under. It’s extremely good at being what it is and if that aligns with what you want it’s fantastic. If it doesn’t, it probably isn’t.
Commuting is a good point actually. If I was still commuting by bike I suspect I’d use it a lot- one hour rides where you want something to keep the chill off to start, but wouldn’t want to stop and de-layer halfway. Waterproof enough o get you home in all but the worst and min8mal faff of dealing with multiple layers.