Almost 100% of the new equipment we're installing is H/P or Barker. I've set up quite a few of these EEVs recently.
Suction temperatures have been moving upwards over the past 10 years or so.
Meat cases used to want to run at 12 degrees SST. Now, I'm setting them at 18-20SST and getting the same or better product holding times. Better designs.
Newer case, I'd start at 18 SST or so, and see where it goes from there.
What I'd do is measure the SH. If it isn't high then I'd either start by replacing the transducer, then the temp sensor OR, I'd do as blackmira suggested and break out the Q kit, IF and ONLY IF, the case is over 12 months old.
Our company got burned on one where a guy did that. H/P rep walked in, looked at the case and said "You modified it, warranty void" Customer made us put an EEV back in the case. Almost all of us carry transducers and sensors. One guy in each region carries a laptop and a dongle.
Lately, I'm tending to agree with Phase Loss. Hill/Phoenix sure ain't all that excellent on the quality side of things. Too many little details that aren't right.