X15 speed

The title is no exaggeration, I did a speed test before and after on speedtest.net.
With the integrated wifi my Dell laptop (fairly recent) work: Download 2.39 Mbps, 0.07 Mbps upload.
With this USB wifi antenna: 34.87 and 3.35 !!!
Suffice to say that I did not expect so I was just hoping to win one or two bars on five of my reception. I wavered between 1 and 3 bars, with regular disconnections. Now I am to 5 bars, oscillating between 94% and 100%, usually 99%, all without having changed anything other than the wifi antenna.

FYI, I am running Windows 7. When I plugged the Windows 7 wifi antenna has not found a driver even through Windows Update. I chose not to use the mini-cd included in the box because I had read negative comments about the manufacturer's drivers: I have instead taken the latest drivers from their site (perhaps the same as on the cd for that matter). I also downloaded their connection utility.
I then went into the Windows hardware manager, I found the unrecognized hardware and I indicated to Windows where to find the drivers I had to download. It moved smoothly.
But why not install all this via the CD, if it is it works very well also and this is anyway bcp simpler.

In short, after qques hours of use I can say that I am blown away by improving the connection.

FAI: Numericable 100 Megabytes (about 40 Megabytes max in practice).

PS I unplugged one of the antennas to see if it made a difference: a priori we lose nothing, at worst qques% on the quality of the connection. The second antenna it would be for show?

UPDATE 16/09/2014: I see qques disconnections on my laptop with this antenna. I will not be surprised either because the current supplied by the USB laptop is not very strong, to see on a powered USB hub by transformer. Since I bought a repeater (it is less than $ 15 or 17 euros here) that works very well. Even with the repeater, I earned 10% with this antenna but I prefer not to win 10% and no longer have the unwanted disconnections. In addition, the repeater allows my phone as well pick what obviously not allows this antenna.
I suggest therefore rather the repeater, which can take as easily as this antenna but requires an electrical outlet where the wireless signal is still strong.
I will try this antenna on my hub powered and I will update my review.