Their
website is stating that this is a "Special Launch Promotion" so there is probably not much in the way of feedback from users available yet. [unless anyone has used (or even heard of) these Ztorm guys before?] I would be interested to know how anyone goes on, though.
I grabbed that free games pack from them and downloaded all 4 of the games (well on the last one; at 92% percent).
It's very simple to use. You download a small (~3MB) download client thing which downloads and installs the game for you.
However you have to download in one go, you can't quit and start back on the same place, and you can't pause the download. So unless you can download straight.. it might be a problem with larger games.
Atm, I can leave my pc on 24/7 because I'm in halls so I don't pay for electricity, but for one of the games, I had to leave it on for over 2 days straight so if I had to pay, I wouldn't have done that.
Side note: How odd, I just tried to google 'dixondownloads' but their website doesn't come up lol.
Anyway, I'm not actually sure you can access the installation files or if you do whether you can install it yourself, because the client downloads, extracts and installs it for you. Someone will have to clarify. However, if you can't then you'll have to download the game again if for whatever reason you needed to.
Some games however (I think for the smaller in size games) asks you where you want to save the game temporarily (with the option of not deleting it after installation).
Haven't played any, but just loaded up one of the games and it started without any problem.
TL;DR - Easy and simple downloading; speeds are good. Games start w/o a problem. Only niggle; can't pause / restart downloading and may have to redownload to reinstall.