Shotcrete is a prepared mix with larger stone aggregate and is pnuematically applied. Its actually a stronger product. Gunite is often eyeballed on site and applied differently. Usually a wetter sandy mix and not as strong. Any water added to any cementatious product above manufacturer spec weakens the product. The advantage of shotcrete is it's a spec mix you know what your getting. Often the 2 terms are used loosely and generalize oncrete pools
In Australia we exclusively use shotcrete, it’s premixed to suit application. I’ve just had a shell formed and are now waiting for the pebble. Gunite to me is a bit more like the on-site mixer, 3 shovels of this, one of that, three of this and some water till it looks right. Having said that the waterproof pebble coat comes next and I believe that is mixed onsite. Sometimes choice is burden, in the end both will produce a finished product you’ll enjoy for years.
Here's my thought. There is sometimes a lot of discussion about which one is better by a pool owner, PB, etc. But after the fact, I've never read one single discussion of an issue caused by using one over the other. I'd give it zero of my energy and no consideration in the decision making process.
I'm not ignoring the potential differences, but in the real world of pool ownership, there is no difference. I'm not a PB, but have read many thousands of posts here with no mention of issues with either after a pool was complete.
One aspect you, or we, didn’t ask or compare was price point or cost. I had two quotes for the pool build we are still in the process of and there was almost a $10K difference. I assumed there will be a bit more management with the lower cost but I can easily reallocate the $10K. Point being that if either option is significantly cheaper, and your happy with both contractors then that would be a deal maker fo me.