Well I am very reserved about giving ultimately bad reviews, but since this site is on here, then I gotta pitch in, since I did have genuinely bad experience with them.
These guys sell cheap shaped web-hosting plans. With typical promises like disk space, up-time and reliable support.
Well out of three mentioned here, disk space was the only one they didn't manage to screw up.
Long story short, I've been a customer of theirs in 2003-2004, paid for a year's worth of hosting to get a free domain promotion. Well, the troubles began soon after the initial set up. I used the service to run a forum board, PHP - mySQL based. Half the time the site was down, because the mySQL database was set up on a server with probably 20 thousand other websites, trying to share system resources all at the same time. That didn't work well, and since the site was dependant on both the web-service and the database, it was not up 99.9% as advertised.
After complaining to tech support, they did move me to another mySQL server, and then they moved the rest of the 20 thousand complainers. So 2 months of uninterrupted service was all i got for my year worth. I switched to LunarPages and used them, and recommended them to all my friends.
As well, I recall having troubles getting my domain name transferred from Gisol, I left it with them to ride out the year, but once it was due for renewal, they only provided an option to renew with the service, then made a claim that the domain name belongs to them. Fortunately for me it wasn't popular, and after letting it expire, and waiting for a 3 months of Gisol using it for fake advertising, I managed to re-register it, and kept on using it for the next 4 years.
I know my experience is less relevant because of it's age, but if you take a look through current review around, Gisol did not improve much, even though they had 6 years to do so. The company literally survives on customers letting them keep yearly subscription fees, and getting 2-3 months of service then running for the light at the end of the tunnel.