Nice to meet you via TFP
G3 will tend to get caught some of the time in corners or against steps. Fine in freeform with all or mostly curved surfaces. Thumping effect bothers some people (annoying noise when amplified by a glass pool fence!) The big flap does some brushing/disruption of the surface (good thing). Very simple and easy to maintain.
MX6 works pretty well and does a bit of brushing/disruption of the surface. Long skinny debris gets caught in impeller and stops it (e.g. stuff that falls off palms), easy enough to clear, but worth noting. Needs specified flow. I wouldn't hesitate to recommend it for a screened pool.
Aquanaut 200 - no personal experience. Hayward bought Poolverneugen, which made the "The Pool Cleaner" which was highly regarded, and have made some recent changes, so not a lot of experience to go from directly. No brushing, just vacuuming, other than a bit of tyre spin.
I would add mine - Pentair Warrior (Rebel) which is pretty much a direct copy of "The Pool Cleaner", same comments as above. I expect this next comment applies to both Aquanaut and mine, but I've found that it works fine at vacuuming the floor at well below the specified flow rate. Needs specified flow to do walls (but I don't vacuum walls

) Good hose (never tangled) and I've found the Pentair hose to be better than Jandy/Zodiac. If running well at low flow is important, this or the Hayward is what I'd recommend.
I don't have experience with them, but there are happy members here with the Hayward Navigator and the Hayward Aqua Bug.
If you didn't already have a DE filter, or you want brushing mostly done for you, a robotic cleaner would be worth considering.