I recently purchased a 455 Rancher (not the 455e) wanting a step up from my little Echo 18 and being as its the largest model sold at the local Harry Homeowners superstore. Being times are hard these days I first tried the Poulan Pro 20. It was a nice saw and I felt cut better than my Echo 18 inch through the big hardwood oaks that dot my lot, but the plastic toolless chain tensioner seemed cheap to me, and turned out I was right. At least in my case. I had used it twice to fell and buck some midsized 20 inch oaks when on the third use the tooless chain tensioner snapped when I accidently got the bar pinched slightly. Once it was broke the chain would no longer tighten. Turns out its a somewhat common complaint with these saws, even though Stihl apparently pioneered the technology. So when I went first to look at the Husky 455 Rancher I was shown a 455e, with the toolless chain tensioner and I said, "oh no, not again". Fortunately I found buried in the back a 455, which still uses the standard bar nut and tool method, which to me seemed to always work well, so I went ahead and snatched it up.
So far I love this saw. I'm disappointed that a saw this heavy won't take a 24 inch bar per manufacturers recommendations but I am not disappointed with this saw. I paid 379 for mine, and for the money it seems to be just a really great midsized saw. Starting it is incredibly easy, hot or cold. I thought my little Echo started easy but this thing is a one pull wonder. It's a little heavy for it's bar size but I find the weight a plus as it makes you pay attention to what you're doing more than a lighter saw, which I tend to get too relaxed with. What I really love about this saw is the cutting power. I didn't think going from a 46cc engine (on my Poulan Pro 20) to a 55cc engine would be a huge difference but it was. It effortlessly breezed through all the larger hardwood trunks I threw at it, and I do mean breezed through. It tooks mere seconds to go through 20 inch and larger oaks and just seemed to run better than my little Echo (which is a good saw). So far its been a great saw, so based on the other reviews in here I'd say you're going to be very happy with it.
As for the 455e with the Toolless Chain Tensioner I can't say whether or not it works ok, but I'm sure it's probably fine, but for me the 455 with the standard chain tensioner was a great buy.