Product review (5 stars): just like original except for the grease
Dec 25, 2014 : the original failed a bit too early, but had been grease packed at the factory, and it appears that the grease "gelled" and slowed the idler wheel to the point that the belt slipped.  The new one came ungreased (and was installed ungreased - we'll find out if that was a mistake :-)).  Replacement was easily accomplished (watched on-line videos)  and the dryer is back up and running.  quick shipment btw. thx!

Dec 31, 2016 (two years later!):
well - I have my answer... I've had to replace this again (from a different supplier - still appears identical)... this time I've greased it.  I've left the 5 star rating as I consider this was a "self-inflicted" injury.  interestingly enough it was the shaft/axel that failed - the liner of the wheel itself was obviously harder than the axel... however, the wear caused wobble and then the plastic of the wheel also developed grooves.  You might also consider replacing the belt if you have this idler wheel fail - but I don't think it is a requirement - the belts appear to be pretty robust.