Cannondale Flash 3 (Alloy) 26er OR BMC Sportelite SE01 Deore/SLX 
Please help! Seeking advice. I am deciding between these 2 bikes as I want to get into mountain biking in Hong Kong. I have been biking mostly for fitness on flat paths so far and would continue this as well and hit the trails on weekends.
The issue I have is that I can get the BMC paying by monthly installments for 24 months and the bike costs US$1288, whereas the Flash 3 alloy costs US$1740 and I can only get that one financed for 12 months. So the BMC is much more attractive budget-wise, but I'm not sure if it's really as good or if it's equal to the Flash 3 alloy.
Since you haven't given links to the exact versions of these two bikes that you're considering, I did a quick Google search to get an idea. From what I can see, the Cannondale has a version that comes with an unconventional fork that, instead of having the usual dual stanchions for suspension, is "suspended" somewhere near the crown (above the "forking part of the fork"). It looks to me like this couldn't provide any more than a couple of inches of front suspension travel, and might not even be the best two inches of travel that you can find. If that's the version of the Flash 3 that you're considering, to my eyes, it appears to be meant more as some vibration/bump absorption solution for someone who wants something like a rigid bike but a bit more comfortable.
Meanwhile, the BMC features a traditional mountain bike suspension fork, from what I can see.
I'm not sure if this would make an immediate difference to you, given your style of riding and the types of terrain you'll be riding on, but if your trail riding keeps increasing, that Cannondale's fork might become a significant limitation to you before too long.