For me, a flagship phone needs to hit a lot of marks to be considered impressive: it has to have cutting-edge performance, beautiful design, a powerful camera, long battery life and not be too hard on the pocket.
In 2014 HTC hit nearly all these marks, with the One M8 excelling in every area. OK, it wasn't cheap, but nor was it the most expensive on the market. It didn't have the best camera, but it was the most innovative.
One year on, HTC didn't find itself at the top of any of those categories apart from design, where it still showed the rest of the market how it should be done. It raised the price by nearly 8% and yet didn't deliver any discernible upgrades beyond a more mature camera and slightly more professional speakers. It's all nuanced tweaks, not powerful improvements.
Of course, the HTC One M9 is no longer HTC's flagship phone, so can't be held to the same exacting standards. But it now finds itself competing against a new breed of capable mid-rangers with, in many ways, superior components.
I think I'm most disappointed by the camera used here. I was expected HTC to come out all guns blazing, showing us that it really did believe the megapixel myth was something to be fought, that lower MP counts really do count for something.
Instead of the next generation of duo camera, an 8MP UltraPixel sensor or similar, it seems to have thrown in the towel and decided to try and make more megapixels work… you know, just like everyone else.
This is a phone that has all the DNA of the HTC One M8 and polishes it well. Theme creator adds a lot of personalization to create an emotional attachment with the phone, and the Sense Home widget seems to be really useful too.
I thought I'd be getting rid of it straight away as I've seen this tried over and over again by other brands, but it's actually useful and surfaces the best stuff at the right time.
The main thing I liked is the design though. It was easily the best on the market at the time, feeling almost hand-crafted with a great aesthetic and great feeling in the hand, and it still feels great even now that the HTC 10 is on the market.
And while things like BoomSound, BlinkFeed and Sense haven't necessarily been improved much, they're still really great features that HTC is rightly proud of, showing it's still a market leading brand.
Sadly, there's more to criticize in the HTC One M9 than there was in the previous couple of years. The first is the battery: I would expect strong power management from a 2015 flagship, as shown by most of the One M9's contemporaries, and instead I got something that was a step backwards.
That's a reduction in power with no discernible reason either – the full HD screen isn't any different from last year, the battery is bigger and the software presumably stable - especially now that it's on Android Marshmallow. So why on earth are we not seeing at least 36 hours of battery life where I'm not even getting a day?
The camera is more powerful than I was expecting but I'm still disappointed in the loss of the UltraPixel and duo camera combo. I wanted to see an 8MP advance on the One M8, maintaining the strong snapping speed, and instead I got a sensor with the same specs as the one Sony had been pushing for over a year at launch – although it does take some great pics on occasion.
The biggest issue I have with the One M9 is that it doesn't impress me as other models have. Good design is fine, but it seems like HTC's just remade the phone from 2014 as it didn't have anything new to add into the mix. Taking the DNA from the One M7 and One M8 doesn't mean that's fine for a new handset.
Let me make one thing clear: the HTC One M9 is an excellent phone, filled to the brim with good features, a clever interface and a design that it should rightly be proud of, once again showing every other brand how it should be done.
The issue is that it doesn't improve enough. The One M8 was pretty much the perfect phone, and not much has changed year on year… in fact, HTC has gone backwards on battery life and hasn't really done much more than polish throughout the phone.
Except perhaps in the camera, where things are improved and needed to be given that was somewhere HTC was struggling to gain consumer support. It's now just the same experience as on every other phone though, and I miss last year's innovation.
HTC hasn't been as arrogant as Apple by simply bringing out an S version of its phone though – there are some genuine upgrades, which are evident the second you put the One M9 in the hand. It makes the design of the M8 look sloppy in comparison, for instance.
This is a phone sold on precision, but comes with far too many ragged edges to be considered worthy of a perfect score again.
It's all tweaks and polish, an admission that HTC managed to create something brilliant in the One M7 and M8 and was loathe to deviate too far from that formula. Which is a shame, as this is a brand I've almost come to rely upon to offer genuinely useful innovation time and again.
HTC might not have quite lived up to that ideal in 2016 with the HTC 10 either, but at least it created something new and consistently strong. In its predecessor we got a good phone - a pretty darn good one - but not brilliant.