[quote]CONCLUSION: Our results indicate that 6 weeks (18 sessions) of training using an uncoupled crank system does not result in changes in any physiological or performance measures in well-trained cyclists.
*Edit, added links*
Recent paper, with control and well defined groups:
http://ecite.utas.edu.au/52288/1/Willia ... cranks.pdf
In it they also speculate on the reasons for disparity in the Luttrell and Potteiger paper.