I originally bought the Ink Bird and ended up giving it to my son-in-law and ordered the Fire Bird 2.
A few pro's of the Ink Bird:
- Cost (as you pointed out)
- Built in magnet so it will stick to the gill w/o having to buy an accessory
- Works OK and I'd say the app is functional
Pro's of the Fire Board 2:
- Seems like a more robust and better built unit (at least to me)
- Better app and functionality. You can save your cook info with temp graphs, notes, and pictures
- I prefer the menu system, screen and screen layout options on the FB vs. the IB
- Room for 6 probes vs 4 on the Ink Bird. This will allow you to monitor multiple cooks (even across two grills if they're close, multiple proteins and/or several ambient probes to get a feel for heat distribution
- Better probes and more options (hint: if you buy FB make sure to buy the competition probes - both long and short. They are awesome)
- Good tech support (never tried Ink Bird in full disclaimer)
- iWatch support (I use this a lot)
If I had to do a quick summary, the Fire Board is the "gold standard" and the Ink Bird is a very good value option. I use several pieces of equipment from Ink Bird in my home brewing and it's a solid "value brand".
At least that's my two cents!