HTC p3600i/Windows Mobile 6 review
While not my first smart phone, the HTC p3600i is my first Windows Mobile (WinMo) phone. I put the emphasis on my first WinMo phone, because my mother has an O2 XDA Stealth slider WinMo 5 phone, so I have been exposed to Windows Mobile before.
First, the physical love (p3600i)
It would be unfair to say that I love the p3600i but I certainly don't hate it either. Compared to my mothers phone, its thinner/smaller, lighter, and doesn't get as hot. Compared to the Sony Ericsson m600i (my previous phone), it has a larger/brighter screen, but is larger and heavier. However, unlike the m600i, the p3600i has curved corners, making it fit better into my hand and into my pockets.
One area this phone that suffers (and indeed many of HTC's other models) is tactile input. While it has a good scrolling wheel, and a few side buttons, it lacks a key/number pad. The m600i is/was a horrible phone - the touchscreen was rubbish, the battery life was poor, the software isn't compatible with Vista, and it was sloooow. The only redeeming feature it had (in my eyes), was the QWERTY keyboard input. Adding this to the p3600i however, would either add to the physical dimensions or reduce the screen size, so its one of those undesirable situations: do you make it bulkier, cut down screen size, or leave it as it is? There are other models (such as the TyTN II) that have a slide out keyboard without getting much (if at all) bulkier, but that just adds to cost.
The bottom line is, If you are a heavy SMS'er, or write novels on your phone, steer clear of any phone with just touch screen for input, but if you don't fit that description, it just takes a bit of time getting used to either scribing, or using the on screen keyboard. When I originally started writing this review, I was of the opinion for any text input this phone was a nightmare. HTC's new Touch Diamond phone has an interesting on screen keyboard (in the style of the m600i's keyboard - QWERTY with two letters per key) with much larger buttons (takes up 90% of the screen). It's incredibly usable, and people have hacked it out of the Touch Diamond to work on other phones! While I don't find it as fast as my m600i, I still find it faster than the standard number pad on "dumb phones". For me, this is permanently on now, and I'd recommend it to any WinMo5/6+ owner with a touchscreen only phone!
Battery life isn't too bad, but it isn't too good. It is better than my m600i, but Bluetooth or wifi chew the battery life.
On beating the turtle with a hare (Windows Mobile 6)

(HTC's Home plugin for the Today screen, and the HTC Touch Diamond Keyboard .And yes, I know I spelt Skype wrong,
but at least you know these screenshots are from an "actually-in-use" phone)
When choosing my phone, it basically narrowed down to the Nokia N73 (which would have been 'free' on the plan I was going onto), or the HTC p3600i (which is +$10/m on the same plan). While I could have chosen either phone for a variety of reasons, such as the N73 for better battery life, or probably a better camera OR the p3600i for having a touch screen, the decision was made because one phone ran WinMo, and the other didn't. Why go for WinMo? Well, I'm really getting into the .NET stuff, and I use Outlook. That is, .NET CF runs on my phone, and Outlook syncs with my phone (email and contacts, bi-directional) whenever I'm in range of my laptop.
One thing I've heard over the years is that WinMo's greatest flaw is that it is unusably slow, so I was reasonably expecting that the phone would be unpleasant to use, requiring patience to switch between menus/apps. Either that only applied for WinMo 5 and earlier, or the delays were exaggerated. While heavy multitasking (particularly with a large webpage open in IE, and ActiveSync going) does slow down, the phone/OS combo is still faster than my M600i, although not as fast as my wife's Sony Ericsson K850i.
There are a lot of nice things about WinMo, such as "proper" syncing with Outlook or the ability to write my own apps (.NET CF) a lot easier than I would be able to with Java (since my J2ME knowledge is low). Even Sony Ericsson have realised that WinMo is a very good platform for smartphones over their SymbianOS, and will be releasing their own WinMo phone (…ironically made by HTC)
Bottom line
Neither Windows Mobile 6 or the HTC p3600i are flawless, but they're both totally usable, and even enjoyable to use.
I'd prefer a smaller/lighter phone, with a better battery life, higher quality camera phone, and a slide out keyboard, but I'm not willing to spend that much (money or time waiting for it to come into existence!) more to get it. The only complaint about connectivity is that it doesn't use a standard 3.5mm audio jack, but apart from that, it has connections for everything else (wifi, bluetooth, 2/3g, IrDA).
WinMo6 is good (better than what many claim it to be), but the default interface could do with a serious work over. HTC have addressed this on some of their phones (such HTC Touch series), and the interface can be found for other HTC/WinMo6 phones, but it should be improved by Microsoft and be the default settings.
Internet Explorer is useless by todays standards (either mobile or desktop browsers), and needs a serious overhaul. Apparently Internet Explorer in WinMo6.1 at least has a zoom mode, but unfortunately there isn't a WinMo6.1 ROM for the p3600i, so I'm not able to tell.