Very impressed with 0.7a so far, although that could be said for pretty much every release I've seen--can't believe I've been playing this for almost four years now.
It'll take some time to get used to, just like supply / CR attrition, but the cat-and-mouse dynamic of detection grants the campaign layer an element of tactical nuance it had previously lacked. It's a creative, unique system with no easy comparison to other games, but the mechanic actually feels grounded in realism. There's a clear modern warfare analogue in managing EMCON tradeoffs--in games like Jane's Fleet Command, Modern Air Power and CMANO, balancing the need for detection with the need to stay undetected is crucial for success.
Building on this, since detection is now a key game mechanic, it'd be helpful to have more options for enhancing sensor range / effectiveness. Probably easily modded-in, but I like the idea of a new utility ship functioning as a space-AWACS. More importantly, with the removal of the burn-boosting skills, larger/slower fleets seem like they get 'bounced' constantly--one solution would be increased sensor efficacy for fleets with fighters, simulating radar pickets, CAPs, etc. Heck, that could even be a new ability for the player--toggling fighter stances to trade increased fuel / CR burn for greater detection range.