I spent entirely too much time researching HVAC brands in preparation for replacing our units this year.

Spent a lot of time over at r/HVAC and r/hvacadvice.

The biggest takeaway I got was that all the major brands are pretty darn similar at the end of the day, and that 80% of it is the quality of the install by the company, and the warranty. Also what is popular in your area matters, because you need parts to be available quickly if there is ever an issue. One area may do a lot more of a certain brand than another part of the country.

Lennox in particular is sort of seen as the Mercedes of HVAC. Lots of bells and whistles, but expensive and maybe not as reliable/harder to repair. Not inherently bad just a different niche.

Also for anything above ~15 SEER efficiency, make sure you look up a SEER calculator to assess whether you will ever see a return on the extra investment. A lot of times you won't. Life expectancy is ~10-15 years these days. The more efficient units are arguably less reliable, as they are more complex, as well.

For the other bells and whistles such as 2-stage/variable stage, know that you are paying extra for potentially better comfort, not so much any long term savings.