BlackBerrys and PDAs bad for work/life balance?

On Silicon.com in the past week there was an interesting article about the impact of Blackberry and PDA devices on Work/Life Balance. 

All of silicon.com's 12-strong CIO Jury IT user panel agreed BlackBerrys and smart phones have improved their productivity but warned it can have a negative impact on work/life balance without judicious use of the off-switch.

This observation is critical and centre to some of the debate we've been driving on the moof.mobi site we have.

With increased access to systems and information comes increased individual responsibility in ensuring that increased access doesn't just become an extended tether to the office.

I personally have my device setup for push email during the week between 7am and 6pm.  In the evenings/weekends I manually synchronise when I feel appropriate or necessary.  When I'm on vacation I still take my Windows Mobile device but switch synchronisation off completely.  If I continue to work on vacation - how is it a vacation?

Now there are always critical situations that require me to work outside of those core hours but I can choose to change how/when I access email and other systems. 

I always get frustrated when PDA/Windows Mobile devices get lumped into the same category as Blackberry devices as one fundamental difference between Blackberry and Windows Mobile devices is that you can modify the Push Email experience to suit your work/home life.  With Blackberry it's always on.... (unless you turn the thing off completely) with Windows Mobile you can choose how and when you are connected.