I had some Keo Flex for a while, and the sloppy 8Nm wasn't the problem, even up to 170rpm on the rollers. Although I tend to use 12-16Nm versions, I can't see 8Nm causing me a problem.
I bought two pairs so I have a spare one when they break
I broke the Keo Flex, and some people broke the first generation Blades, but I don't think the Blade 2 is particularly prone to breakage and the spring can be bought as spare part, albeit for more than you just paid for complete pedals.
I had some Keo Flex for a while, and the sloppy 8Nm wasn't the problem, even up to 170rpm on the rollers. Although I tend to use 12-16Nm versions, I can't see 8Nm causing me a problem.