I think it is hard to judge, the only thing swinging it for me is that we haven't particularly missed Keiran Lee IMO - we've had Wabara and Brown who have given us the same amount of attacking threat that Lee did, but also do the right things defensively most of the time.
Lee was prone to getting caught out of position up field and that cost us on a few occasions, however, i would have loved to see how Lee would link up with Croft on the right side - could have been an interesting partnership and would have been deadly in attacking terms, providing somone could get on to their balls into the box.
I'd say we've missed Taylor more than Lee, his threat was always there; even though he had many doubters near the end of his Latics career, his attacking intent was always clear to see - i think we have missed him on the LW with Montano being a very hit and miss player, although Obita seems to be a much worthy replacement for Taylor and has proved to be in the 3 weeks he's been here.