Off the top of my head CL has signed:
GKs
Douglas
Henderson
Ds
Maybury
McCarthy
Gerrbrand
Johansson
Gilbert
Ms
Hughes
Hamill
Kisnorbo
Sylla
Fs
Hammond
Hume
de Vries
Of the GKs, since we didn't have any beforehand, and considering their wages I think we've done more than alright to have two better than average players to pick from.
Of the Ds, Gerrbrand and McCarthy are unqualified successes. Maybury and Johannson have both looked good at time, but have both suffered from occasionally being played out of position. Maybury suffers from playing behind Sylla. Gilbert simply hasn't had a chance to prove himself, he is young and could develop to be something very good, but then, so could Alan Sheehan, so what was the point of buying him?
Of the Ms, Hughes is good but unfit, hardly Levein's fault- although constantly giving him injections to get him to play will cause problems long-term. Hamill has been very positive for a young player bought to develop, he has taken his first-team chances well, by and large. Sylla certainly has shown that he can play, but he doesn't put the work in and this causes problems for the rest of the team, especially Maybury. Kisnorbo isn't up to the job.
Despite a poor start de Vries is now coming good, he should total 15-20 goals by the end of the season at his current rate and makes play for other players. Neither Hume or Hammond have been given the chance, and have been the prime vicitms of Levein's inability to pick a settled side.
So, after all, of 14 players I would say that 7 have been good (Douglas, Henderson, McCarthy, Gerrbrand, Hughes, Hamill, de Vries), 2 have been quite good (Maybury, Johannson), 2 aren't working out (Sylla, Kisnorbo), and 3 haven't had a chance to show themselves (Gilbert, Hammond, Hume)
All in all, and especially compared to our last two managers, I'd call that a good record.