18-1/2 foot boats are fine but they usually come on a single axle trailer which means a bumpier ride while trailering and backing down a boat ramp could be more challenging.

Usually but you can get a dual. I have a dual for mine.

I like the single axle trailer. But I live at the lake. A 20 or 25 mile drive is a long drive to the ramp for me. Way easier to back up and make tight corners. But yes you have to slow down on rough roads!

Single axle trailers suck, but I like an 18’6” boat. Perfect size, and makes my bass look bigger.

Usually but you can get a dual. I have a dual for mine.

I fish out of a 18.5 TZX 190. I bought it in 2014 when it was 1 year old with 22 hours on the 175 engine. I paid $22K for it (which was a steal at the time). I added an Ultrex and upgraded the electronics. It'll hit 62 mph on plane. I've been on big water plenty of times, and with the utlrex it'll hold its own in waves that if they were any bigger I wouldn' want to fish anyway.

So what would a 21 footer do for me?

1. Not fit in my garage.
2. It would go 74 mph instead of 62 mph.
3. It would be slightly more comfortable in giant waves that I don't fish anyway.
4. If I were regularly fishing 3 guys out of the boat it would be more comfortable.
5. If I needed to roller skate up front it would better.
6. Maybe my only real gripe is rod storage which isn't the greatest truth be told in the smaller boats.

Anyway, yes if I won the lotto I'd upgrade to a 21 footer at some point. For me though the 18.5 footer works great and I have no plans to go to a bigger boat. It's a great value at 1/2 the cost of the 21 footers. The only thing that might change my mind would be if I decided to start tournament fishing with regularity and had no choice but to fish big water on big wind days.

that is a fine looking boat.