mobile

Not sure what category this question should go under. :P This concerns my Huawei Ascend Mate 2, on Net10 and using the AT&T network. On Cricket, I could have the same AT&T net strength and I can bring my phone over since it's unlocked... problem is, Cricket says it will only support 3G speeds on my LTE device. Boo :(
But, I would have 5GBs each month instead of 3GBs. I'm weighing which I need more, speed or quantity, and I'm heavily leaning towards quantity, but I want to be sure before I jump in. I'd like a way of testing 3G speed while I'm still on my LTE network, to see if I can tolerate it. In my settings, network mode is greyed out and not able to be clicked. It seems the network switchers on Google play arent working for my device (a couple apps outright said that too, lol), I'm wondering if there's a way I can mod it, or if there's an Xposed Module for this? I couldn't find one, but doesn't mean I didn't potentially overlook it. I'm rooted of course, on stock ROM, running 4.3. All the other questions based on this that I was reading seemed to circle back around to toggling the mode in settings, which is disabled on my device.
Even if I don't go with Cricket, I would still like to know how to slow the network down for other future purposes. :)