Common misconceptions about 'Exchange Push' in Exchange 2003 SP2:
#1. True, about 309 bytes worth of traffic goes back and forth between the phone and the server as a heartbeat signal. The default "rate" is 15 minutes but it auto tunes, so you probably will not see 309 bytes of traffic every 15 minutes for every mobile user. It isn't an e-mail "pull", but a "heartbeat", much like a clustered server checking availability.
#2. SMS is not used at all if you are using native Exchange support with Mobile 5.0 that has the Security and Messaging update on it. Before the update was available, some providers used SMS-piggybacking to give it pseudo-push support.
#3. Get the extended battery. With the standard battery, your phone will not last a full day under normal use. I don't have a Motorola Q personally, but it is a common theme I hear from everyone that owns one.
#4. It doesn't work. If people are telling you it doesn't work, they are most likely trying to sell you on a Blackberry solution, which is fine, but there is a lot of FUD out there.
point 3: the battery doesn't last all day unless you are in execellent coverage. If you are close to a tower, the standard battery can last more than one day.
point 4: this phone has much difficulty if you are near a 1X tower, but just on the boarderline coverage of an EVDO tower. the phone gets quite confused and data transmission stops. this happened to several of us using the Q. its a known problem. Hopefully this will be addressed in the future.