The Jets have played the fewest games against teams currently sitting in a playoff spot (13 GP, with a 7-5-1 record = .577). I'd say that playing the Jets is somewhat detrimental to your chances of making the playoffs, but Vancouver has played the most games against teams sitting in a playoff spot (21, with a 15-5-1 record = .738).
Here are the records vs. current playoff teams of the Top 17 teams by points% (I couldn't include the Caps, who are garbage, and leave out the Pens, who are not...so Top 17). Sorted by points% vs playoff teams:
BOS: 14 GP, 9-2-3, .750
VAN: 21 GP, 15-5-1, .738
VGK: 19 GP, 12-5-2, .684
PIT: 18 GP, 9-5-4, .611
NYI: 18 GP, 8-5-5, .583
WPG: 13 GP, 7-5-1, .577
NYR: 14 GP, 8-6-0, .571
TOR: 15 GP, 6-4-5, .566
COL: 16 GP, 9-7-0, .562
FLA: 18 GP, 9-7-2, .555
CAR: 19 GP, 9-8-2, .526
PHI: 18 GP, 8-8-2, .500
DAL: 17 GP, 7-7-3, .500
WAS: 19 GP, 7-8-4, .474
LAK: 18 GP, 6-7-5, .472
EDM: 20 GP, 8-11-1, .425
NJD: 14 GP, 5-8-1, .393
Yeah the Jets have played a lot of crap teams this year so far, but they've still been pretty good vs. non-crap teams.