So to me it is a factor or where are you from - I am from NJ and I see you are from Tx and what you are used to.
I dive BHB and southern latitudes in a bathing suit and I love it. But folks look at me and give me that eye till I explain I dive in 39 degree water and this is pure heaven. I love the water and the water on my body.
Sure if you are going on a dive vacation - the 3 mill protects you from the sun and the coral but you should have control of your buoyancy and if you do - you dont need the suit. So - if it is just a couple dives and I am done - I go in a bathing suit. If it is multiple days and multiple dives per day - 5 dives a day on my recent vacation - I wear a 3 mill to protect me from the sun...
ymmv