You should not disregard stop sign and stop light functions which adds to capabilities beyond EAP.
Resting your hand at the bottom of the wheel not only keeps the nag from appearing, my hand resting also provides an extra sensing measure for auto steer. If I sense that the wheel is not responding appropriately, I can immediately take over. I have not experienced any of the issues you mentioned and is certainly not annoying.
I would challenge you that AP is solid functionally more often then super cruise is allowed to operate. I just came back from a 700 mile highway road trip all on NOA with 0 disengagements, phantom braking, issues in general. Where NOA/AP struggles are in scenarios that super cruise wouldn't even dream of operating; construction zones, lane shifts, really any situation where the roads were altered. AP handles those situations really well with added attention by the driver.
This is an extreme disadvantage. It would really be annoying when most of my trip is not mapped for use. This in itself would make the cost not comparable.
Traffic light and sign response will be really useful once Tesla adds unconfirmed go on green for stop lights, and go from stop signs. I don't expect to see that happen until FSD beta is released. I don't currently use it because its too prone to false detections, and so it adds to phantom braking.
What I find really frustrating with AP is just how mixed the results are. Where 5 people will have 5 different experiences.
With the Model S I didn't have any frustrating with the nag. Sure I didn't like it, but I wasn't frustrated with it. It was quite easy to find a comfortable yet safe position to have my hand(s). On the Model 3 I really haven't, and I've tried the commonly suggested hand at the bottom.
With TACC/AP I get rather random phantom braking. For awhile there it seemed to be caused by large semi's in the lane next to me. It was to the point where I preferred my Jeep Wrangler Adaptive Cruise control over the Tesla TACC. For awhile it seemed like the events were reduced or lessened in severity (they were never major events, but enough to cause annoyance).
NoA could be made a lot better if they simply allowed users to report glitch points. If I drive north from my house there aren't that many glitchy areas, but if I drive south (or north back to my house) I find numerous points where NoA has issues. This is even ignoring all the construction going on in Tacoma.
Most of my miles are on major highways which are all mapped. So I'd be really surprised to run into any issues with a hands free system like Supercruise.
Now I'm not switching anytime soon as I'm holding out hope for improvements with FSD beta, but competition is heating up. In fact I think FSD is really what's pushing the competition on both pricing, and capability. So people will be able to use Supercruise without having to wear a gold chain.