Has anyone installed a cellular booster?

I just ordered one of these cellular boosters for our 179, mainly so we can watch DirecTV Now on the AT&T network:

https://www.ubersignal.com/surecall-fusion2go-3-0-4g-extreme-rv-signal-booster-kit.html

I was wondering how people have mounted the outside antenna. It appears that the included bracket could be screwed into the side wall of the camper, but I ordered one of these to be able to mount it further above the roofline:

https://smile.amazon.com/gp/product/B003D1QPHK/

I'll likely put the amplifier in the dead space behind the stereo, connected to inverter I installed there for power.

I'm curious it it will really work.  I called Verizon some time ago and asked about signal boosters.  The technical support person said that will help in buildings with blocked or weakened signals, and may help push an incoming signal a little farther.  But when I explained that I was hoping to be able to strengthen the incoming Verizon signal signal in areas where the it was very weak, he said that there is really nothing on the market that would help go from a very weak signal, like 1 bar bordering on no service to 2 or 3 bars of signal strength, if the base line signal is very weak.

Cellular boosters like this are a crap shoot.

First, you need to know where the nearest cell tower is. This is not always knowable. At any rate, you want the external antenna to be highly directional. A directional antenna will be several times more sensitive to weak signals than the omni that is in your phone. It will also reduce the interference that will be generated by your nearby phone.

Which leads me to the second issue. The indoor antenna and the outdoor antenna need to be isolated from one another by any of several means: (1) Using an outdoor directional antenna, (2) Separation by distance (hard to do in an RV), Separation by RF-opaque material (fiberglass RVs are not very RF-opaque).

I've been involved in setting up a number of cellular boosters. I've seen instances where a $250 system works great (because all the issues are favorable), and I've seen instances where a $10,000 system did not work at all (where all the issues are UNfavorable).

I've seen much better results when using a femtocell, or WiFi calling for services & phones that support it.

Well, the outdoor antenna on that one looks like an omni, you it will hurt you for the outdoor antenna. The other issues you already have a disadvantage. So I would not hold my breath. Be sure to give us a report if you try it out.

I should be able to test it in less than a week. I'll be in an area with traditionally weak cell service. I don't plan to install it permanently for this test so that I can return it if I don't get significant improvement.

It should be possible to retrofit a directional antenna if nothing else.