To answer your question; if you're looking for a 18650 mod that is going to last you 6 months to a year, get the SID. However, if you're using Pro Tanks, watch screwing the heads down too far or you'll push down the pin in the SID the same way you would on a Vamo.
I have a Sigelei Zmax mini. I love it and wish I would have bought it in the 18650 size as it only takes 18350's. However, after a few months of heavy use, the button begins to misfire and it goes into the menu while I'm firing. It happens about 10% of the time.
IMHO, I'd pass on both of these and get an MVP. I've spent a lot of money trying to find the right mod, only to have them break and malfunction. My MVP is very versatile and reliable and is delivering what I had hoped. Instead of trying another $50 mod, I just sprung for a Semovar. Hopefully that will replace all of the dead Vamo's and Sigelei's I've lost along the way.