Without any doudbt the tested Globalsat GPS products are very good products and will satisfy their buyers. Each one has its own buy group, depending upon the needs of user. If someone wants to use a GPS device at both PDA and Laptop, then the BT-338 or BC-337 are the best choices. If the connection interface is Secure Digital, then SD-502 is a perfect match.

The BT-338 will probably be the best choice for most users, since it unitlializes a strong battery, being able to powerup to 17hours the device, features auto-turn off and showed excellent performance either installed at the car panel or inside a glove box. Its small external sizes making it truly portable, so you can carry it with you anywhere.

The BC-337 uses the compact flash interface so it can connect at PCs and PDAs without any special problem. When someone use the included external antenna will enjoy perfect performance with low TTFF times and high sensitivity...Lastly the SD-502 is a product, mostly aimed for PDA users, it also includes a 512MB on board memory for storing your maps or logged data. While its performance was not the best at this roundup, we can live with it.

BT-338

The Positive

• Complete retail package
• Car charger is included
• Very good performance
• Easy installation but user should read before the included PDF
• Powers it self off automatically!
• Included battery can last up to 17hours!
• Small dimensions and low weight make it portable

The Negative

• No input jack for external antenna

BC-337

The Positive

• Input jack for external antenna
• Very easy installation process
• Complete retail package
• Includes PCMCIA adapter
• Can be used at both laptops and PDAs
• Very good performance (especially with external antenna installed)

The Negative

• Not as fast and accurate as BT-338 (without external antenna)
• Doesn't work under WM5, be careful!

SD-502

The Positive

• Complete retail package
• Includes 512MB storage on board
• Small dimensions

The Negative

• Average performance, its TTFF times are rather high
• Can be used only with PDA devices
• Check the compatibility list before buying it, be careful!