Over last few years I used two Mobitel 1290 packages to connect two computers to internet. We used two mainly for extra bandwidth and speed. With introduction of Mobitel Mega plans, After dropped one connection and upgrade the other one to 20Gb package. It let you use multiple SIMs with same connection.
Our 3G dongles were from stone age, and speeds were limited to 7.2Mbps down-link and about 300kbps up-link at best. Ofcourse these are theoretical numbers and the down-link was much slower. One of the dongles was too old to work with windows 7 and we are down to one. It was time to upgrade devices.
New device of choice was Huawei E3551 portable 3G WiFi router. Here is what I liked about it.