However, if you are going to play more than one round a day, or have a habit of forgetting to charge things, then getting a combo unit is a real plus.
Note: Combo units are a little larger than rechargeable (only) receivers as they include a battery compartment.
Next, let's assume that your handheld includes embedded support for Bluetooth, has a Compact Flash slot, and a SDIO slot. It is time to ask yourself if you "walk" or "drive" a golf cart most of the time during your rounds of golf.
If you drive a cart most of the time, then we would suggest getting a Bluetooth GPS receiver.
First, you will need to determine if your handheld includes support for Bluetooth (i.e. If it does, then adding a Bluetooth GPS receiver to your system is a real possibility (more later).