These forums have been incredibly useful to me so I thought I would contribute this. Maybe somebody else will find this helpful.
I was a Bluehost customer for over a year. My two cents are that Bluehost is good for a certain type of customer, bad for another.
The pros are it was cheap and reliable for my static content sites. When I say static content, I'm referring to brochure-like sites with an amount of nodes that don't increase much day-to-day.
I started to noticing the cons as I one of my sites grew. The site involved forums which demand considerably more CPU power than a site with content that remains largely static.
Even though I worked hard to streamline Drupal and the site as much as possible (turning off statistics, views, etc.), we hit Bluehost's CPU ceiling very quickly. While Bluehost offers unlimited bandwidth, if offers very limited CPU. My site slowed to an absolute crawl.
I realized that I needed to upgrade to dedicated hosting but had to work with Bluehost while I got things sorted out. I tried to work with their tech support to make some improvements to the PHP settings.
Bluehost tech support was always friendly and prompt, but I did not feel like they were very knowledgeable. I am hardly a hosting expert, but I felt like many times I was talking to somebody who knew less than me.