A little late to the party, but just finished 'Travelers' last night having watched all 3 seasons over the last week or so. I'm going to assume I don't need spoilers now as it's quite old. Stop reading now if you've not seen it yet!
Quite a good ending although, it was a little 'it was all a dream' type thing, in that in the end they just undid everything they'd done. I didn't mind this though. I didn't actually like Marcy and the David meeting up on the bus, as that wasn't the Marcy he'd fallen in love with. To me this meeting at the end meant nothing... but all in all, a good ending still.
I did enjoy it, but it surprises me it's 8.1 on IMDb. I usually think anything on IMDb over about 7.5 must be pretty special. That's not to say I wouldn't rate it maybe 7.5, but IMDb is usually a tough crowd. For me it was a little over dramatic and a little convenient at times. The episode with the wiped memory felt more like they had the ep idea and then tried to work a story into it, for example. Still, all in all, for a 3 season (32? eps?) show it's worth a watch.