I put a lectron on my YZ250 and love it. My kid's, and wife's, machines can't accept one or I would get it for theirs. I did not have to do any tuning with the meter length or the power jet. I still like to pull my sparkplug after a ride and it's always that creamed coffee color, or the slightly gray rich.
I know how to tune a carb but damn sometimes it's a lot of effort tuning everyone's machine to be good for sand dune riding. If we only did trails I could accept how the carbs are set and get away with less tuning. Some trips I have to do all the main jets and needle clips on the kid's and wife's quads. I keep a log of the settings and weather conditions so I have an idea if just needle will get things done or if a different main jet is needed. I don't have enough elevation change to have to mess with pilots and most of the time I can get by with adjusting the air screw in the morning then move it back after it has warmed up in the day.
My biggest gripes with the Lectron is that the choke is on the wrong side of the bike and draining float bowl could have been made easier.
The smart carb fixes my gripes about Lectron but I don't want to spend another $700 to replace a carb that already does what it said it would which is auto compensate.
The smaller 2 stroke engines I have are the most noticeable when the jetting isn't on. The 90cc and 105cc often need some tinkering the first morning of a trip. The 400cc is harder to tell jetting could be better unless you set out with the intent tinker with jetting. The guys I know that have been able to put an auto compensating carb on a small cc bike have similar results as I do with my 250. My YZ250 is smooth with no bog from 60F to 105F and +/- 3000ft from my home base elevation.
I would say to have reasonable expectations of the carb. The auto compensating isn't guaranteed to keep your plug at optimal color. The auto compensating takes away the bog feeling that is what indicates you've got a traditional carb circuit to tune. If you're after peak perfect performance with nothing to adjust I don't see an auto compensating carb giving you that. With an auto compensating carb you'd still be making minor length variations or rod taper changes to chase perfection.