i love the phottix mitros+. it has every feature of a modern flash, but it comes at premium. i love the fact that it can be updated via usb, supports external power and can control groups from the flash. its the best of both worlds because you can use a flash on camera when you need to. you can control/trigger other flashes if you need to and if you have the odin you can control/trigger your mitros+ and other flashes if you need to.
if you want a flash with that is much cheaper with similar capabilities i would look at the Yongnuo YN568-EX II. It does everything the mitros+ can but it has less power, no usb, no external power and it can't control/trigger other flashes via radio. it can trigger via optic, but no remote control though. that is why i went with the mitros+.
when the Yongnuo YN-600EX-RT is released it should be on par with the mitros+ if not exceeding it. the problem is that is has been delayed (currently 7 months or so).
so if you only need to trigger other flashes via optic and you don't want to go over $300, go with the Yongnuo. You'll be able to get 2 for the same price as 1 mitros+. but if ever want to be able to trigger and control multiple flashes via radio you may want to spend a little extra and go with the mitros+ or the YN-600EX-RT when it is released.