I went ahead and tried the approach recommended here, and looked at Howson's first round picks in comparison to the two players picked before, and two players picked after. Seeing where Howson's pick fits in with this group of five might be the best way to assess the quality of his choice: if his pick is the third best of the five players, then he is average.
2007
Alzner
Gagner
Voracek
Hamill
Couture
I'd say Voracek is second out of this quintet, although he isn't much ahead of Gagner or Alzner. Voracek had 4 assists today. Alzner is sometimes billed as top pair with John Carlson, but wasn't that good last year, though he still can get better. Gagner is a big scorer with the right linemates, but Edmonton fans never shutup about wanting to dump him for a bigger center.
2008
Pietrangelo
Schenn
Filatov
Wilson
Boedker
This is an easy one. Filatov is a clear bust, and fifth of five.
2009
Kreider
Josefson
Moore
Schroeder
Erixon
I would take Moore first here, although Kreider and Erixon could ultimately end up better. I wouldn't have taken Moore first before the season, but he has been the Jackets steadiest defenceman many nights, while Kreider doesn't seem to have much hockey sense.
2010
Seguin
Gudbranson
Johansen
Neiderreiter
Connolly
Is Johansen better than Gudbranson? I have no idea. I would take Johansen second here, although its too early to tell.
In sum, Howson's record is average at top picks. I haven't applied equal rigor to it, but I would guess Howson has done above average with picks outside of the first round, finding guys like Calvert, Atkinson and Jenner.