I would choose the digicool, (i have had mine for 6 months), also purchased a Mastercool (now returned as it was difficult to read and some minor calibration problems which it should not of had being new), as it has features that the digicool does not. (vacuum input, usb port for recording)
I find the digicool the easiest to read in a wide range of conditions (large digits and a good contrast) and data all on a single screen
Accuracy seem very good across the range. with both LP/HP reading very close.
It would seem all seem to have problem measuring temps on small pipe sizes (as have many, built my own sensing mechanism)