I am a diafine freak. Loved it for years, never had a bad experience with it. Just remember to go full term with each solution. I think the instructions say a min of 3 minutes each (A&B) I usually go 4 minutes, it gives me fine results.
From 35mm to 4x5, I use it more often than any other developer. Just renewed my 1 gal suppliy after 1.5 years. I bet it could go longer but for 5 months it sat idle as I had other high priorities with my mom and dad's health.
Running two rolls of TX100 tonight in 120 format. Shot at box speed.