For a couple of years, I've been using a Joe Rocket Phoenix jacket for 90% of my riding. With the liner out, it works well in the SoCal heat, and a Sahara vest does wonders on those really long, hot days. With the liner in place, I'm comfortable on cooler days, and when it gets even colder, I put on a fleece pullover under the jacket. On really cold days, I have much heavier, 3/4 length textile jacket, but I haven't worn it much lately.
A few weeks ago it became apparent that the Phoenix jacket needed replacing. I went to NewEnough.com to check out mesh jackets, and came across the Tourmaster Flex jacket. In it's standard configuration, it's a full-up textile jacket, with CE armor in the elbows, shoulders, and back. When it gets hot, you can zip out the textile shell from the chest, back, and arms, leaving you with a Phoenix-style mesh jacket. On colder days, there's a two stage liner - you can zip-in just the rain liner, or add a full-sleeve quilted insulated liner. It's got the standard complement of pockets and reflective piping.
I've only had it for a week, but so far I've been impressed. In the mesh setup, air flow is as good or better than the Phoenix; with the textile shell in place, I've ridden comfortably in 50 degree weather. The insulated liner is very warm. It seems sturdier and more protective than the Phoenix, and matches up nicely with the Hein Gericke HT Air overpants I use.
Tourmaster Tech jacket