Personally I’d stick with the tried and true 14 seer, maybe as high as 16. Unless you have the finances and you just really want it. But I would not view that stuff as an investment.

The only high seer equipment that has consistently been phenomenal is Mitsubishi. And I know they merged with Trane but until Mitsubishi irons out some Trane stupidity I’d stay away from the Trane high seer stuff.

By the way I forgot you said “American Standard” because my brain just instantly converts that to “Trane”…just FYI an American Standard is a Trane.

 

If the outdoor unit is on backorder, more than likely it will be an X series as well. I don't know that you will gain any useful operation out of the X series over the previous generation. I believe it's more for technicians remote monitoring and wireless access to information on the equipment. It is supposed to update firmware on the equipment remotely as well, opposed to having a technician physically connect in order to do so. Good luck getting the equipment in a timely manner...

 

I've had good luck with the Trane/American Standard 20 SEER stuff. Not many issues. Mitsubishi has nice ducted systems too, with tough to beat cold climate heat pump performance, but I much prefer Trane's controls and airflow management.

They are in a transition period now where they are moving to the "X" series equipment. So it will be common to have the new generation units matched with the previous generation units. The new ones are backwards compatible with the previous generation communication and the 1050 thermostat, so no problem there. I wouldn't worry too much about getting the SC360 thermostat, there looks to be some cool diagnostics stuff, but honestly most of the benefits are for the technician rather than you as the homeowner. And it's brand new, so who knows how many bugs it might have that still need to be worked out.

 

FYI, these are the part numbers they put in the quote, so I put them in this original post.

ss120396: Thank you, I'll drop the Thermostat concern knowing it'll be compatible now.
mgenious33: Because of your post, it spun off a question in my mind....

I cannot determine the new "X" model number for the condenser, so does anyone of you professionals know what it would be for the American Standard 4-ton 48k BTU XV20i "X" series heat pumps? It's not anywhere online nor any manuals about it available anyway for me to lookup. I'll take that information to my dealer via email and follow up about it. Maybe they know, maybe they don't. Maybe they assume, maybe they don't. Most likely, Trane/AS won't be shipping any previous generation off the line from what mgenious33 is saying. Basically, logistical back-ordering and inventory is more of a pro thing plus their experience, I can only ask educated questions and learn... Thanks everyone! I can tell you folks really love this trade!

 

I cannot determine the new "X" model number for the condenser, so does anyone of you professionals know what it would be for the American Standard 4-ton 48k BTU XV20i "X" series heat pumps? It's not anywhere online nor any manuals about it available anyway for me to lookup. I'll take that information to my dealer via email and follow up about it.

The model number for that unit would be 4A6V0X48A1000A.

I'm glad you asked, because it prompted me to look up the documentation for the X units. Turns out I was wrong in my previous post about the compatibility - I had it backwards. The new X condensers are backwards compatible with the old air handlers and 1050 thermostat. But the new TAMX air handler is not compatible with the previous generation condenser or the 1050 thermostat. The TAMX would need to be matched with the new X condenser and SC360 thermostat.

 

First, thank you very much ss120396 for your research.
I contacted the dealer. When it was all said and done, this is the equipment matching list (amongst other things):

American Standard - Platinum Series 4 Ton, 20 SEER, R410A Variable Speed Heat Pump Unit, 208-230/1/60 4A6V0X48A1000A
American Standard - Platinum Series, 4 Ton Variable Speed Multi-Position Air Handler, R410A, 208-230/1/60 TAMXB0C48V41DA
UX360 Link Smart Thermostat THUI2360A200U
SC360 System Controller TSYS2C60A2VVU
Electric Heater, 20kW, Breaker, 24V Control, 1 Ph BAYEABC20BK1
Supply Duct Flange C BAYSUPFLGCA
Single Point Power Entry Kit BAYSPEKT200A
Internal Condensate Switch Kit BAYICSKIT01A
Low Voltage Conduit Entry Kit BAYLVKIT100A

AHRI 19.25 SEER
All this seemed compatible. The lead time is a few months, but my current system still works meantime.
He offered to upgrade the 22 year old vapor line from 3/4" to 7/8" (AS recommended size) but said it was probably was not worth the cost and he'd just clean it.
There is an option for the American Standard AccuClean Whole Home Air Cleaner AFD235CLAH000C, but it was kinda pricey...

So, this thread resulted in a complete rework of the quote. He said that AS/Trane already notified him of the incompatibility and just never got around to reworking the quote.