I was one of those previously with a definite preference for the lower BB setting, despite most of my riding being single track and not predominantly downhill orientated. However, now at last, I can claim that my E150 Forks and AFR Shock are running as they should and I have relentlessly fine-tuned the compression & rebound for both in order to get the sweet-spot for my general riding style, I have totally changed tack on this;
Previously, with either poor-running or ill set-up E150 Forks and AFR Shock, it was nigh-on impossible to pedal efficiently with the BB fitted on the higher setting
However, (for me at least; at 6', around 190 lbs on a large framed Enduro SL Pro), with the supension fully sorted; the seat height very high/XC style (ie, when the pedal is at its lowest point, the leg is nigh-on fully extended when seated); the seat set well forward on the rails and the bars similarly tilted slightly forward (in order to get those shoulders forward/pretty-much in line with the fork setting dials when aggressively pedalling), I have now become a convert to the higher BB setting
For me, in this configuration this bike can be ridden all day and at great efficiency/speed and my riding mates with SL's have also become converts and gone this way too. You have the benefit of the greater ground clearance on a bike that will fly on the trail and up-hill climbs;
However, I found an initial down-side to the set-up described - Due to the relatively unusual 'sit-up & beg' riding position & general geometry of the Enduro SL; when you first set up the bike in a manner described; it can feel like a mistake because although you are using the same muscle range as normal for pedalling, you are using the muscles either slightly more extended or slightly differently proportioned/pronounced to what you may commonly be used to. Therefore, after the first ride it feels like really hard work and the rear-top of your Adductor Brevis (rear thigh, just below the buttock line) and low spot on the Adductor Magnus (area leading towards the knee) will feel particularly sore for these reasons. However, if you persevere for say four 20 mile hard-push rides; these muscle areas become accustomed to the slightly different expectations put upon them and pedalling becomes far easier and much more efficient
Hey, I'm no Physician so don't sue me if you end up with six weeks off work, in traction in a hospital ward But if you feel you aren't getting good efficiency from your Enduro SL's pedalling I would recommend you trying to adopt this set-up principle to your own body make-up and give it a whirl; after-all, you can always use it for comparison and revert back
At the end of the day, bike set-up is pretty much a personal preference thing and without doubt, the Enduro SL has a lot of adjustment options to be tinkered around with to the heart's content