Without a Cryosleeper, Coronal Hypershunt, AI cores, or colony skills other than Ground Operations, they're still good, mostly thanks to all the cool domain loot you can find. In terms of story point investment, I only improved the Megaports on all colonies and Commerce on my massive money maker. It's 20 in-game years in so they build up pretty slow, and I still haven't found a Pristine Nanoforge or Light Industry booster, but having 400k income and 350k of production capacity per month for very little babysitting or investment other than money and exploration loot is good. Barren rockballs are some of the best cash cow planets now because of all the industry items that require vacuum/non-habitable, and I like that colonizing gas giants is now something you might seriously consider as a good source of volatiles instead of being the worst way to get volatiles.