Hi Redstaar,
sorry for the delay in getting back to you - been on my hols!
I'm not sure how many people that have bought one use the forums, but the feedback that we're getting on them is really good. I've put a link below to the customer reviews page for the universal one.
Clip Antenna for Huawei USB Modems - CRC9 Connection Reviews & Comments
I've used the CRC-9 one with my E169 dongle on 3, and it added 2 bars to my signal strength at work (went from 2 to 4 bars) and at home it added one bar (from 3 to 4)
Obviously the improvement it makes will depend on where you're using it and what the signal strength is like where you are.
From the scenario you've described though, I'd say that the high gain one will suit you better. These make a bigger difference to the signal that you get, as long as they point in the direction of you networks transmitter. These are a newer product and we've not had any customer reviews yet for them - if its any help, we've sold 51 since we launched them and only had 4 returned as they'd ordered the wrong connection type.
3G High Gain Directional Antenna - Universal
Hope this helps