I have the Thunder Pro Ultra Compact .45, bought in about 2011 or so. Good gun, never had a problem with it. The 9mm is the same general design as the 45. When practicing, I shoot it one-handed both left and right hands, and two-handed. Never has a problem with jams or cycling. I find it to be quite accurate when fired with 2 hands using the sights.
I like the DA/SA action. It has a decocker which doubles as a safety. The DA pull is reasonable, but enough resistance to feel safe carrying it hammer down and safety off, if you are concerned. Or you can keep the decocker/safety engaged, and just flip it down when you are ready to fire.
It has an issue (if you want to call it that) where it shoots true to point of aim. The front sight has a white dot. The bullet will go where that dot is.
Meaning when shooting targets, if you put the bullseye on top of the sight picture, it will appear to shoot low.
So you have to cover the target with the front sight. The sights are not height adjustable, but the model I have is compatible with SIG sights, so I could replace the front and/or rear sights to move the point of impact up or down to my preferences. Or replace with tritium sights or any other SIG compatible sights.
I was not concerned enough for either the cost or hassle of doing that, so I just adapted to how it naturally is sighted.
I also have the Thunder 380, purchased around the same time. It is a different design, but same company. One of my favorite pistols. Fun to shoot, accurate, reliable.
Both are decent guns for the price, or were when I bought them. I don't know what the current state of affairs is for parts or warranty work.
They are both fine firearms when considered on their own merits.