I'm very happy with my lowly 600 , a 650 or 700 would be a bonus for me.
I wouldn't own a blackberry based on what 2 friends have said about them
after getting them free from thier respective companies. The treo has some
shortcomings, but not enough to make me ever want to change:

Those being , recently at work my signal strength dropped with Sprint PCS.
The phone battery goes dead connecting, losing connection and reconnecting
and its a bit hard to turn off the wireless portion as they call it. (I call
wireless
802.11) they call wireless CDMA.

Very easy to navigate as I said. I like the one handedness over the two
handed
always ppc. It has a touch screen like the ppc. Keyboard is awesome. It
scared
me at first look as I have big fingers, but I shortly got used to it, Its a
two handed
keyboard, but phone, web, contacts navigation is definately one handed. Type
the first 2 or 3 letters in while in the contact list and it filters for you
!! Very Nice !!

I like being able to install a myriad of 3rd party apps on it and even with
its
seemingly small memory compared to PPC phones, the programs that run on
it are very tight i.e. small and fully functional, customizable. I use
tinysheet at
work a lot for figuring out traffic signal timing in the field. In my old
job as
an instrument tech, I wrote a spreadsheet that would calculate resistances
for RTD's or resistance temperature devices. A very complex equation for
platinum precision devices. Also for my 4-20ma to engineering unit calcs.
Very Very Handy.

The broswer on it, blazer is very good at displaying web pages and loads
quickly, given a good service area. The 650 comes CDMA or GSM depending
on what carrier you want , but Sprint can't be beat for 15 a month unlimited
i-net
on the phone. CDMA .

I also like playing card games , and the palm has a lot of those along with
some
adventure games and scrabble, bowling , etc. while waiting in line anywhere.
Even in
the car waiting for the light to change I play a round of rummy lol.

I'd buy another Treo no questions asked . PPC's have left a bad taste in my
mouth
from old. Theyr'e probably better now but my most recent ipaq 3760 is rough
on
batteries and I hate activesync. The palm desktop is a perfect PIM for me.
The transflective
display is a bonus on PPC's if they have them , but I can turn the
brightness up high enough
to easily read the palm display on a very sunny day in direct sunlight.

Its easy on batteries as long as signal is good. I have over 500 memos in
mine from everything
and the calandar rocks. not your outlook wont show the whole year calander
that ppc uses.
It has customizable alarms, very customizable to the point of being more
useful than outlook
which always tells me when a meeting I need to go to happened (past tense)

PPC and windows are tightly integrated, Outlook notes are a total mess
whereas palm notes
can be categorized. In fact everything can be categorized on the palm. Nice
!

Good luck with your decision.
I'm beat , its 1 am and work tomorrow 11 hrs. Ugh. Excuse any spelling errs.

EP