With regards to each area of responsibility in "who he gets"...
Personnel Selection, Amateur (the draft, prospects): Obviously too early to evaluate, but this is looking unbelievably awesome so far. I have no worries here.
Personnel Selection, Pro Additions (roster guys): Kind of neutral, leaning towards good. When adding new guys, so far the return on investment has been limited (Howson had this gift of consistently finding castoff depth gems; JK doesn't seem to do that as well, judging by how his Euro FAs have gone so far). Obviously going for Gaborik was a major whoopsie. That said, one must admit that guys like Comeau, Skille, and Hartnell have fit in just fine (even if he allowed Skille to briefly depart), and Gibbons is starting to look a whole lot better too.
Personnel Selection, Pro Subtractions And Retentions (roster stability): Overall OK. He's made some controversial selections, but none that I think are all that substantially bad. I mean, I miss Vinny and DMac and kvetch about keeping Boll as much as the next fan, but I'm not seeing how they're the difference between life and death or something. Keeping a close hold on guys like Letestu, Atkinson, Calvert, Anisimov, Savard, and Dubinsky rates higher to me, as does his willingness to pick Skille right back up after he was put on waivers (tho I would have preferred no temporary departure in the first place). And I for one no longer miss anybody who left via the Gaborik trade.
And w/r/t responsibilities in how he gets/keeps them:
Contract Negotiation and Extensions: F***ing brilliant, IMO. I think we have a definite upgrade on Howson here. The only black mark I can think of is that the Johansen negotiations got a little twitchy. If that pattern continues with other players, then maybe we have cause for concern, but unless and until that happens I'm happy with his performance here.
Trades: Some are decent, some not so great. JK's "disaster recovery" hasn't been at the level of Howson's, to be sure, but Howson's was pretty damn awesome so that's probably an unfair comparison. He's had some very nice little tactical trades on draft day, and one that looks like a major success (Hartnell for Umby), but also one experiment that did not work out at all (Gaborik).
Free Agency Acquisition: Not enough data to fairly evaluate. We've had a number of low-cost tries that haven't worked out, but that's been at minimal cost to the Jackets organization. And for the record, I do NOT give him a black mark for Horton, because the first year's shoulder injury was a known and planned-for issue, and the back condition came out of nowhere. Linking the two is absurd; it's more indicative of a slavish obsession with narrative quasiconsistency on the part of those making such an assertion rather than anything grounded in reality.
So basically... he hasn't been the epic badass that the narrative used to suggest, but he's hardly poor quality either. I'd give him a B average.