I first tried Maxthon about 4 months ago and was impressed but still didn't use it much.  Lately, though, I've started using it as my main browser.  I've been experiencing some slowdowns on my connection over the past few days, due to some work the cable company is doing, that have caused many slower sites to timeout on both IE and FireFox but in Maxthon they come up fine and fairly quickly.  Also, while I haven't done any benchmarks to compare with either IE or FireFox, I can honestly say that Maxthon feels much, much faster in most cases.  They have a bunch of plugins (I haven't tried any of these), theme customization, screen capture, file sniffer, ad hunter, filter packs, etc. 

 Just to be clear - I have no affiliation with Maxthon.  I'm just a fan of the browser so I have no problem promoting it, that's it. 

Click the image below to check it out