GDL 39 vs 50?

As a follow on to my previous question about Garmin show specials... Does anyone know what the difference is between the GDL 39 and the GDL 50? I realize the 50 is the newer device. But are there any operational differences? Thank you!

Operationally the differences would A.) the data port settings are different for a hardwired Garmin device receiving data (Connex 5700 vs Garmin data or something like that). B.) The GDL 50 has attitude information built in whereas the straight GDL 39 does not (the GDL 39 3D model does). C.) The GDL 50 has a built-in backup battery while the GDL 39 has an option to add a backup battery that piggyback onto the unit. The GDL 5x units manage battery charging and use better than the 39. And D.) The GDL 5x units use smart logic to turn the unit off battery power after flight while the battery option on the 39 requires the pilot to remember to turn the unit off after flight either directly or through an optional remote switch that grounds the gray wire in the GDL harness.

Both units are compatible with the same hardwire GDL cable option(s) so they are plug and play with respect to their power/data port with the caveat of changing port data settings per A.) above.

The data provided is the same although the hardware in the GDL 5x series is newer and smoother than the older hardware in the 39. Bottom line is if you already have a GDL 39 it is probably not worth the upgrade unless you are wanting attitude (non-GDL 3D) or look to add Sirius/XM weather and music by selecting a GDL 52 model. If you are starting from zero then common sense is it's worth the extra money for a 5x unit.

Attitude

The GDL-50 is supposed to have a faster processor that gives improved attitude information but I never really noticed the differance from my old GDL-39-3D

Hey guys. Thank you very much for your very informative response. I ended up purchasing the GDL 50 today.