Hi Norm, Quite happy with the antenna, it makes the difference between having and not having internet most times.
Before the external antenna we relied on the one built in to the HUAWEI E5372s-32 pocket wifi.
As far as a clear line of sight goes, I'm not sure what the definition of that is. I can tell you the globe tower is about 2 miles away with trees and buildings between us and the tower. The antenna is mounted 30 feet in the air on a bamboo pole, i guess it might be possible to see the top of the tower if i was 30 feet up with binoculars?
The sim cards come in 3 sizes and are used in phones, usb sticks, pocket wifi's, modems, and tablets.
When/if you bye a pocket wifi or modem your sim chard might have to be changed in size. Adapters can be used but you risk damaging your sim card contacts inside the device, so for the sake of a couple bucks just get the proper sized sim and perhaps save yourself future grief.
If you only need the internet at home get something like a Huawei B593s-22 modem, if your needs are for in and out of the house then look at a pocket wifi like the HUAWEI E5372s-32. Both of these have internal antennas and external antenna connections. These 2 units will work with globe and smart in the Philippines. I can personally vouch for both of these units.
There are many pocket wifis and modems on the market using various frequencies and bands that will not be compatible with smart and globe or may not have external antenna connections. so choose wisely and remember you often get what you pay for.
If you decide to deal with Uplift, make sure you get the proper length of cable and the right adapter pigtails for the modem you choose to use.