I have lots of experience. I'll help you out.
First, their deals are good. For $10 or $20, you can get monthly Web hosting, use of your own domain name, use of their DNS servers, etc. You get a fair amount of bandwidth, although even a medium-successful site will have to purchase additional bandwidth.
They try to be VERY secure with server access, so there is NO telnet. You have to use a secure shell client (like Telnet, but uses encryption). However, because their "control panel" is so tricked out, I just use that. You can completely manage the file system through their Web-based control panel.
They have online discussion forums and a knowledgebase, so you can get answers at 2 a.m. if you need.
As for PHP, its good, and regularly upgraded. It was at 4.0.3, just went up to 4.0.4pl1 a month or two ago. You can use a .htaccess file to change around the php.ini settings, and it seems to work nicely for me.
MySQL use at hostrocket is great. They have a Web-based control panel for that, too. I've been able to easily set up tons of tables and browse the data using their tools.
The bad stuff -- there isn't much, but I do think the company is a bit overloaded. The mail server sometimes blocks outgoing email for an hour or two. And the Web servers seem sluggish. For instance, right now my site (www.outshine.com) consists of two lines of text on the home page. That's ALL. Yet it takes about a 5 second lull before the page displays. However, once you get "in" the site, subsequent pages seem to display fast, so I guess the problem could be just a sluggish DNS server.