Several years ago, I got a spypoint. It was one of 3G models, which don't work on 4G or 5G networks. I got a year and a half of function from it before the cellular towers got rid of the 3G signal. I didn't know this at the time, so I spent a lot of time trying to get in touch with customer support. Calls were routinely 1 hr+ before I got tired of waiting and hung up. Never did get to talk to someone in a dozen tries. I know the 3G issue was my fault for not seeing that the cam was bound to be worthless in time, but I had to do a lot of online searching to figure out what was going on... in my experience, Spypoint customer service is non-existant. Admittedly, this was 2 years ago, may have improved, but I'll never need to find that out.
I ended up going with ridgetec. Got the model with both ATT and Verizon chips. Every time I've called customer support, I get in touch virtually immediately, they know my account by my phone number before I even tell them who I am. Questions answered in minutes. A+ for their support. I'll be buying their new model when it hits the market to add a 2nd cellular cam to my fleet.
No experience with the other cellular brands...