Since the changes to defenses things have been more fun I worry less about losing planets. It also costs me more if I want to take one. having been on both sides of the fights I feel on the whole the changes were a major improvement.

There are some major issues that still need adjusting.
1)How defense scales, at the moment defense can scale to very insane levels very fast I've seen over 100k in defense on a planet.
This mostly happens because defenders attributes are doubled in addition to the planets. now that an planet shield adds 750-1200 before being doubled this seems excessive. If the defenders we simply added to the planets stats I think this would be better. I know for smaller legions and lower level players the doubling might be important, so perhaps an artifact for planets that addresses this somehow.

2) The planetary vortex deflector, this artifact under the new system is too powerful. For instance a planet can add several hundred extra attack, add 50% to the population (which can push it into the 2000+ range at high levels,) and have it all restored after invasion. Which when coupled with doing only 1-2 damage per attack makes retaking a planet very daunting.
Now there are artifacts that make it easier to invade like QBV wormhole emitters and cluster missles but they can't be used with the Deflectors up. So essentially if someone takes a planet they have time to fortify it rebuild the population the make it immune to attack.

My point is I'm fine with retaking a planet and and spending artifacts to do it but the PVD essentially means the person who popped it now dictates the entire battle which seems imbalanced.

There are a few ways I see to address this a) shorten the time a vortex deflector works, b) change what it can block, c) split it's function into a couple different artifacts only one of which can be active at a time, d) introduce something that allows the stripping of this defense.

a) This change in timer means that the conqueror doesn't automatically dictate the entire course of the battle. Either edit it to half the time it is now or say have a random chance for it to end each hour like 5%.
b) Tying back to issue #1 with wormhole artifacts blocked by this you can't eliminate a massive boost to the defense until you've burn huge amounts of energy/hull/shield etc. If the planet is immune to things why is this coverage extended to the people in orbit as well?
c) Maybe it's too powerful to disallow the blocking of artifacts, but a simple blanket block seems to be too much in the defenders favor. So if you split off the effects into a few different artifacts which forces the defender to make a choice about what he wants to block.
d) if the saboteur class for example could also remove this it would make them a more desirable feature as it stand right now getting a planet down to 100 pop can be the hardest part.

3) This is really an issue because of the other two points above. But only being able to attack a planets defenders after the planet is down to 10 pop and then having to keep it under that when for example the planet has so much bonus defense and attack becuase of defenders.

3.5) keeping a planet under 10 pop when its regening and your hitting it for one damage an attack.

Anyway these are my thoughts at the moment, about where after the wonderful improvements made earlier we can fix the rest of the system so things don't become so lopsided.