The VLX is an AllStyle brand air handler, not made by Carrier. The FF1 is a Carrier brand air handler, same as the outdoor unit. I can't explain the price difference. Not like the AllStyle air handler costs much (if any) more money than the Carrier. I would want the matching Carrier air handler. The AllStyle air handler will likely work fine, although I can't find any ratings on that matchup, if there are any. It was likely used due to the small space constraints.

Thanks for info so the carrier one which is quite a bit less is really better ..can you find any ratings on the the Carrier FF1 and outside unit? Yes it was used cause of the current Lindell was installed when built and is smaller..several installer s had a cuse word or two over that one..I am planning on moving in a couple of years so moving to attic would have been best choice ..can you believe it was only 300 more dollars for a trane 13 seer moved..from carrier allstar quote..pays to shop around..

Here are the ratings for the 25HCB324 with the FF1ENP025 (the 010 at the end of the model in your quote is just the electric heater size):

11.5 EER, 14 SEER, 8.2 HSPF
22,600 btuh cooling capacity
23,600 btuh heating capacity

Do you have more details on the Trane quote? Model numbers, what's included, etc.? You are right, it is certainly good to get at least 2-3 estimates to compare solutions and products.

Yes it s a trane xr13 --size 024 shp..quote 5882.. mote replace hvac necessary drywall acces and repairs..includes all labor taxes and material..thanks for asking.. the carrier with small handler was 3900 so ..big difference..with relocating to attic..