Red iso sucks and is completely useless. You get maybe 1 new 2 star support every 6 months, and forget about 3,4, or 5 star supports unless you can be top 5 PVP season. Feels like I get more red iso than regular iso. I have 718K and climbing, with no hope of ever using it.
Meanwhile, nowhere near enough hp to keep up with shields and slots.
All that complaining aside, the extra 4 star in progression is awesome. The 5 star shards are awesome.