After HTC released the 20013 One (M7), their next product in the same family was the HTC One Mini and this was followed by the HTC One Max, to complete the family. The One and One Mini had quite different specifications with the One Mini being very much a cut down version of the One; it offered a lesser screen, processor, memory and camera compared with the One. The One Max, however, might have been expected to follow the Samsung model, whereby the larger device is more powerful, has a better display or some other improvements. However, HTC released the HTC One Max with the same quad core, 1.7 GHz Qualcomm Snapdragon 600 processor of the original One. At the time, some fans were surprised and disappointed that HTC didn't upgrade the processor to the new (at the time) Snapdragon 800 to offer that bit more to customers. And now HTC may be doing the same thing again with the HTC One (M9), which we believe will be announced in March, and the HTC One (M9) Plus, also known as the HTC Hima Ace Plus. As such, we might reasonably expect the HTC One (M9) Plus to be based around the Qualcomm Snapdragon 810 processor with a screen somewhere between 5.5-inch to 6.0-inch, but launched against a backdrop of the newer Snapdragon 815 or 820 processors.
One of the other features that's expected on the One (M9) Plus is a fingerprint scanner. We saw something similar on the One (M7) Max but for the 2015 edition, HTC may be including a very Samsung-esque looking home button under the screen. This might replace one of the BoomSound front face speakers, although it would surprise me if HTC dropped a speaker for a fingerprint sensor. We've already seen how BoomSound has evolved over the months, going from a relatively large speaker grill to a much smaller one. The images of devices that we are seeing appear to be prototype models so we may well be seeing how HTC are experimenting with designs. At least one handset appears to have dual rear cameras, so perhaps HTC are going to provide the One (M9) Plus with a duo-camera setup similar to the One (M8)?
As for when we will find out... that remains uncertain. We believe that the One (M9) will be officially announced in early March, but sources point to the One Plus not being announced until much later in the year, presumably to capture some of Samsung's mindshare with the rumors of their next Galaxy Note model that will start to circulate in September time. I for one would hope that HTC will reveal the One Plus sooner than this, before Qualcomm launch a new Snapdragon processor and the specification sheet looks outdated at any rate.