Thanks for your collection of thoughts. It has been quite an experience moving to this amazing machine.
1. What a great machine! Would I spend half-again as much for a G3 based upon what I've read here? I really don't think so-
I, too, am absolutely delighted with my A3. It is an amazing upgrade from the Andreja Premium. After one month with it, I find that it is unbelievably forgiving. And that is a very good thing since I offer it much to forgive!!!
2. Like you, I also have an Andreja Premium. We use it at our vacation home and you (and others) are right, with the Andreja I counted during the flush (one-thousand-one, one-thousand-two) but with the A3, I simply listen to the water dance. My Scace and Fluke combo helped me to zero in on and memorize just the right "sounds" for the temp's I was trying to achieve. This will be obvious, but I've learned to use different sounds to obtain consistent desired temp's if the ambient room temperature has varied a lot (winter vs. summer time). Also, watch it if you're doing a "wiggle-rinse" of the PF after pulling your shot as it is possible to over-cool the grouphead if one gets carried away with this. Fortunately, this behemoth recovers quickly and doesn't hold a grudge like my Cimbali Junior did.
The Scace Thermofilter was invaluable to me in confirming appropriate temp surfing technique. Its ability to reliably repeat my target temperature makes this the easiest HX machine I have ever used.
3. Yep, this machine is picky about its "diet" and is sensitive to overdosing. I just about can't make the A3 serve me anything but fantastic espresso unless I overload the basket (currently using a LM ridged double). I've tried a bunch of tampers and my A3 likes a gentle convex curvature the best (mine is an RB) and a flat based tamper the least well.
I initially had problems with overdosing while using a flat tamper. As suggested in the review and by other contributors, a convex tamper solved that issue quite handily. I use one with a gentle curve.
4. I use the WDT, then tap the grinds lightly a few times to settle my espresso "mound", followed by a Chicago chop, then a couple of light finger sweeps across the basket top to get rid of the loose grounds, then tamp- but have gotten away from tapping the basket at all between my tamps. (My memory tells me it was Abe C. who kindly suggested "No tapping please" to me)
I, also, use the WDT but just use the straight edge on my stirrer to level the grinds. I, too, have recently eliminated tapping with consistently better results.
7. Another way to look at points # 5 and 6 for me is- the A3 seems to perform best if you simply let it do most of the work and spend less time fussing with tapping between tamps, sweeping method, tamp pressure applied this or that. I know it sounds almost too good to be true but as in point #1- what a great machine!
I couldn't have said it better myself!
Enjoy your A3!
Many times in my life, I have "over purchased" or in other ways experienced buyers remorse. I can truly say that this fantastic machine qualifies for neither. It is a pleasure to use on a daily basis. I keep looking for excuses to have friends over just so I can pull a few more shots!
Thanks again for all of your thoughts.
Charles