Michael White wrote:
I have a one-story 1,900 sq. ft. house in North Texas. I'm thinking of
replacing my 20-year-old, 3-ton, SEER= 9 Lennox air conditioner.

I've been told to replace it with a 4-ton Bryant unit. Any comments or
recommendations?

Thanks.

By whom? A Bryant salesperson??

Shop around. Learn about SEER, brands, reliability, what you need for
your house, factors based on where you live, etc. How expensive is
your electricty? Where do you set your thermostat? Is your house well
insulated or can you improve that for less money? Or should you do
both?