First of all, let’s check some table comparisons:
OBDSTAR P50 is standalone version, don’t need to drag a PC. CGDI tools are based on PC.
OBDSTAR P50 is good tool, with very good documentation for connection to unit, have frequent upgrades.
P50 will do some high-end cars, Maserati etc. Some airbag models still requires soldering.
CGDI CG70 is an airbag-specific tool, it only does SRS by CAN. CG70 covers more srs than cg100/cg100x. CG100 do more mcu, eeprom and odometer. CG100X is the update version of cg100, cg100x adds more srs, eeprom and mileage models (i.e MQB NEC355XX mileage).
CG70 software is simple and easy to use. No dismantling, no welding. cg70 have a lot of airbags without soldering.
CG100 and CG100 are good tools and do good job for Asian cars Honda Toyota on bench.
In sum, each one has a option, all good at the end.
Both obdstar and cg release regular updates. Make sure to keep the software up-to-date in order not to miss the latest airbag modules.
Sometimes you need more tools, if cg100 does not contain some of ECUs, cg70 or p50 will do.
For most airbag units is to use any eeprom and mcu programmer, like carprog, iprog, Xprog or Upa. About 80-90% its a direct eeprom programming, sometimes you will find motorola mcu like HC08 family. Some newer units have spc560 or Renesas, those are harder and need special airbag programmers to make the job.