I am Andre Fourie, CEO of Poynting Antennas. The antenna should cause a substantial difference IF your signal was weak to start with. The modem you use is a 14.4 Mb /s HSPA which will give real downstream of around 8 Mb/s and upstream of about 3 Mb/s under ideal conditions. If you already had this level performance the antenna cannot improve the speed - it will always improve consistency and reliability since it is externally mounted and not susceptable to indoor signal variations etc.
The "MC style" refers to the type of connector on the Globesurfer. The Poynting LPDA-0092 comes with a SMA connector (male). You need a small cable with SMA connector on one side and MC on the other to link antenna to modem.This is all that is meant by MC - I assume you have been supplied with this cable otherwise it would not be possible to link the antenna to your router.
The only other issue is whether you are pointing (or Poynting :-) in the correct direction with the LPDA-0092? This antenna should point to the base station of your service provider withing a +-20 degree accuracy. Best way is to look at signal strength while rotating the antenna by 45 degrees at a time. Wait about 30 seconds at each angle! Most modems take time to report performance so be patient. If the antenna points the wrong way you will actually decrease performance.
The huge advantage of the LPDA-0092 is that it covers all frequency bands from 700MHz (USA LTE ) to Europe LTE starting at 800 MHz through 900 MHz GSM , 1700/1800 bands, UMTS,, 2.3 GHz, 2.5 GHz etc. This means it works regardless of location or provider.
If you want improved speeds go to modems with higher data rates at HSPA or best (in Sweden) use LTE modems. These can take you to 100 Mb/s. There you need two antennas like the LPDA-0092 which are polarised differently (mounted horizontal and vertical if you look at the elements). We are also now manufacturing integrated LTE antennas covering all the bands with two antennas in one panel (see www.poynting-europe.com) or contact them for more info.