Ok...here's a more extensive report:
Get a random minisdump on start once in awhile.
On a larger map (huge, eight player vs ai) whenever a ship ability is selected within a gravity well, the game hangs for a few seconds while it processes. Once the ability is clicked and activates, all returns to normal again. It didn't happen at the very first but after a half dozen planets had been reached.
On the huge maps, ships crawl very s-l-o-w-l-y. You can't speed it up in combat cause it becomes a turn baased game at that point and the computer takes its time for its turn.
At the start, the expensive upgrades make it become a more important strategic decision as to whether or not to upgrade. At higher stages, upgrading a single planet can drain you dry. I like the concept but here are some of the effects of the top of my head:
Resources on the black market are very expensive to buy. They also generally fetch a good price selling them and here's the effect of that--you can sell resources and finance huge fleets/rapid tech research very quickly once you have a small but steady supply going but it takes awhile to upgrade the planets due to the cost. So buying resources devours credits and makes it slow to hit higher stages of planet development. Selling resources makes it possible to supercharge building fleets and constructions and research which are much cheaper than the planet upgrades.
The planet slots for logistics and tactical open up in small increments and each increment can get a LOT more expensive. There are very spare tactical slots at lower levels--two or three items consume them. Some upgrades that are quite expensive allow you to maybe ad only a single additional tactical item. This means when the Vasari are ready to deploy phase gates that the cost of upping planets to have enough slots to hold them is ridiculously high. The alternative is to use starbases as platforms for this but then you lose other capabilities of the bases.
So the uptick is that the game is fleet driven--planetary items past a certain level just aren't worth it unless you have a very secure position (as in you are an eco for a team and won't be fighting frontline while they also defend you).
The magnetic (I think) clouds disable abilities but they have asteroid fields within them--only you can't use them because your ability to man them is deactivated (probably why they don't spawn resources in vanilla).
The planet ring colors are sometimes so bright they wash out ships and details which is a real hindrance in combat wjhen trying to keep track of lots of activity.
many planets have gravity wells so large that to phase block them requires all your tactical slots and still leaves gaps. I can see sometimes this as a feature but most worlds are large and effected this way.
Just initial observations and plenty of room for disagreement and discussion on points. I notice the AI seems to take awhile to get up to speed too (on hard anyway) but they do it with a vengeance when they get there.