I like YC1's answer about being overloaded. I think they tell you in the manual to have the outside Antenna separated by a certain amount of distance for best performance etc...
The WILSON SLEEK is a passive close proximity connection to the device which could open the door for being overloaded by a close-by signal in the same frequency range...
I use the same 3G setup using the MIFI 2200 and up to five connected devices when we are in travel mode as well as being parked at our camping location... The WILSON SLEEK with its outside antenna being our docking station for the MIFI 2200 gives us great coverage around our camp site using our tablets etc...
If we want to setup on the beach somewhere just grab the small MIFI unit and pack along in the shirt pocket works great with our tablets sitting on the beach...
Usually have great performance however the MIFI 2200 is not the fastest connection. Even in its best connection situation it is very slow for us to use.
Does what we want it to do for a good low price of $27 a month for a 3GB data plan with Verizon being grandfathered over the past few years... All we need to do is check our emails, keep in touch with the kids, pay a few bills, and do some limited searches on the internet. Not good enough to do any downstreaming of HDTV or movies etc...
I do however load it down with a couple of my favorite BROADCASTIFY LIVE INTERNET RADIO SCANNER channels with no problems... Always like to keep touch with our local Home town Police and Fire Dept/Rescue situations when we are gone...
Roy Ken