Observer wrote:

I was told that a 1/2 ton upsize is not a big deal. In general do you
agree? I'm guessing the a/c guy who spoke with me is correct.

If your installer is using a rule of thumb or telling you 1/2 ton plus or minus
is no big deal, you need to find one who knows how to a do a Manual J and Manual
D evaluation of your home.

If he's oversizing - especially in Houston - you will be short cycling and a
prime candidate for mold. If he undersizes, you won't like the lack of cooling.