I believe after two month you probably already made your choice, but for anyone else who will be searching for the same answer.
So, I had comustar and avital in my previous cars, everything works great till... it’s not. The main problem is that if something goes wrong you have a bunch of random wires, shitload of isolation tape everywhere and no chance to figure out why it’s not working. Even the most reputable shop will never properly solder those wires. And yes, you will definitely loose your warranty as soon as dealership will see all that mess. Aftermarket systems should be connected at least to ignition and breaks, something dealerships don’t want to see spliced.
OEM system from Ford is plug-and-play, you just need to plug it into your OBDII, it has approximately a mile working radius, can be bi-directional, or even work through the app on your phone. You also will get a passive alarm system as bonus.
I am to cheap to just pay 600$ to the dealer, and hey, where’s the fun in it?
You need control module, antenna and the fob. Part numbers you can find on this forum. In my case I bought used control module with t-harness for 30$, new antenna on ebay for 50$ and a bi-directional key fob for 70 (you can find it cheaper). 150$ in total, but you also need to activate it through Ford IDS system. If you have the IDS software you can easily do it yourself, or pay 60 to 130$ to the dealership.
If somehow it will stop working I know for sure what to check. All the wiring is untouched same as my warranty.
Hope it will help someone to make the decision.