Yes, everyone has heard of One&One - its too big a company to miss. But it also has a lot of unsatisfied customers but considering their huge huge customer base running into millions I do believe its reasonable to expect a certain percentage of attrition and dissatisfaction.
They offered 3 year free hosting in the US as a promo offer a few months back - but inspite of that failed to meet customer expectations in the US. But they are definitely very big, lot of customers and is the largest hosting co. in Europe.
I have not heard anything about oneandone myself, however, before you make any decesions regarding choosing a web host, maybe you should search in some more web hosting directories for more Correct information.
Here are a list of some of web hosting directories that come to mind:
Check out findmyhost.com too... They verify hosts on there. Like for my company, they have you submit a request and set up a sample account and go through it and use it to see if you're a countable and worthy web host. Then of course they try and get you to be a guaranteed host by paying or whatever.. but verified hosts are good too.
Yes, I wasn't gonna go, but in the end I decided to move, because I fed up changing companies, 3 companies in 2 months(and that's ~ 800 MB moving over & over to servers, I'm not going to mention them now), so I thought this is not going anywhere and I ordered P4 2.8Ghz box, 512 RAM, Windows 2003 , Plesk panel all in total comes to $130 a month, tough but I just almost earn ~130 bucks a motnh on my site, so it was risky, but that period is gone, and guess what? Since Middle of July : Uptime is 100% , that's what I need first, before any other thing and I think all people will agree without uptime the site is nothing, has to be in 99%-100% range.