I fly the Olympus flag. There are only a few of us here.
Olympus is a company that's been around since 1919 beginning with microscope production. They have a strong camera and lens making history as well, specializing in making neat, smaller cameras throughout the decades of the last century, which they saw as a need for many (which still rings true today). When they began making dSLRs, they strayed a bit from the rest of the crowd, as they always had. They developed a "4/3" sensor style which enabled a smaller, lighter camera. Along with that their dSLRs offered some industry leading technology such as in body Image Stabilization, automatic (sensor) Dust Reduction and Live View (features initially scoffed at by others, then copied.) Today, they are a worldwide leader in medical scopes (with obviously excellent glass), but they recently created an industry breakthrough with their mirrorless cameras (which again, were also initially scoffed at, now every brand is developing). Just as a background into Olympus, and part of what attracted me to them.
Choices (of entry level dSLRS) today are much improved and varied over what they were when I first began looking in 2007. But back then, I definitely wanted smaller and innovative, and Olympus fit the bill. Given that, I don't think I would do anything differently if I had it to do over again.
Seeing that I was coming from using a Canon S3IS - which I loved - when I made the decision to go to a dSLR, I figured I'd move on to a Canon Rebel (the XT at the time). But at the time, I couldn't wrap my head around that particular purchase. Granted, the Rebel was a top seller, but it didn't have many of the nice features the Olympus E510 had. And I researched for months. (I happen to love research!) Olympus made more sense for me from a features and personal shooting style perspective, and what sealed the decision was the ergonomics - how it felt in my hands. I loved it from the first time I picked it up and that was really important to me. Having never used an SLR before, I was nervous about it. I knew I needed to feel comfortable with what I was using if I was going to learn this new skill to the level I wanted to, which was in-depth. I was relatively pleased with my pictures once I learned how to use it.
Several months ago I upgraded to an Olympus E30 and I love it. There's still a ton I'm learning, but the transition was much easier than the one from bridge camera to dSLR. I plan to purchase of an Olympus PEN (mirrorless w/ same sensor as E30) which will allow me to have a smaller, yet very capable set up using all of my Olympus lenses with an adaptor. A Win-Win as far as I'm concerned as I'll have my dSLR as well as a complete and equally capable smaller set up when I want or need it.
Downsides? (Because, yes, there are always downsides to just any purchase.) High ISO performance on the 4/3 sensor isn't generally as good as is on cameras with larger sensors. Was this a deal breaker for me? No, it wasn't. I looked at it as a challenge to see what I could get out of this thing despite this drawback, and that in and of itself, I believe, has led me to become a better photographer: I had to really work for those good low light shots. With that said, the E30 is much better @ higher ISO than the E510 was. I recently shot a friend's theatrical performance at max ISO and was very pleased with the results. (BTW Noise Reduction software is a Must Have for any digital camera user.) Another is that Olympus, in focusing on their mirrorless cameras right now (which they'd be dumb not to), understandably hasn't done much with their dSLRs of late, however as a company they've pledged to continue their dSLR line and hopefully they'll continue their growth and improvement once the dust settles on their mirrorless frenzy. Those are basically my two biggest concerns, but as I've said, I'm not really worried about either or I would have switched brands when I upgraded recently.
Sorry for the "book", but I do like to share what I like about Olympus whenever I can. Most people don't know much about them.