I say go with dual air because its more tunable for your riding style. I currently have the 150mm dual position. Although I like the fork for it's response and feel, my biggest gripe is the fact it doesn't stay at 120 when set. I bought the 150/120 so I can set it for climbing but it doesn't seem to stay but at 150, the rev is perfect.
I have a dual position and love it. Mine has about 20mm of delta and I run it a bit soft and use the low speed compression on the RCT3 damper to stay out of the travel. Depending on where I'm riding, sometimes I'll run a bit more air pressure and back off the LSC or turn it to full open.
I haven't found that the dual air gives me that much more small bump compliance or some other quality that I haven't been able to replicate with solo air and RCT3 damper.
I think the dual air is more significant on shorter travel products like SID/Reba. That's my personal experience anyway.
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