This means that the CPU speed does get throttled back, and the One M9's metal exterior can get warm to the touch when there is a lot of computational work going on. but that hardware is under strict controls to prevent it overheating. Yes, the handset is now running on 64-bit architecture, and yes it is run-on the latest hardware. This appears to be the case here, with the delightful tale of the Qualcomm Snapdragon 810 impacting on the performance of the One M9.
HTC is clearly locked into a yearly product cycle, and this contributes to the relatively small update to the hardware in the One M9. With a reliance on third-parties for the major components, if those parts are delayed or not sufficiently advanced on the model from twelve months before, then the product suffers. As the two-year contracts end, HTC's goal is to recapture those users with a new handset that is both comfortable and reassuring to One M7 owners, but also offers the latest hardware and software. The first is that the real audience for the One M9 are the users who purchased the original HTC One (now known as the HTC One M7). Even a casual look at the specifications and the styling of the M9 is an iteration on from the M8 - there simply isn't a huge jump from last years model, which has led many to question what happened. That means the direct comparison for the media to the One M9 is the One M8. One issue that HTC has had to deal with in this design is the trend to push new handsets out to the market every year.