I have one of the ones with the probe, had it years. It's been used in vivaria, terraria and my current aquarium. Recently, it's about a degree out but it's been accurate until now. Battery lasted a couple of years, easily.
The 2 I have now are 'in tank' ones (as per the link I posted) and they are accurate so far. Only been in there about 3 months so far so can't comment on battery life or whether they'll remain accurate in the long term.
Glass are invaluable but these digital are proving very worthy.. maybe I've just been lucky.