I own a BBQ Guru Digi Q and love it! I do not think you really need it if you have time to monitor cooker all day but with my busy life it is perfect.
I only use the food temp feature on it as a guide. I set it on pork butts at 185 and start to probe the meat at that temp until it is tender.
OK Joe OS, WSM 18.5, OTS 22.5, BBQ Guru Digi 2, Vols Orange Thermapen