No I only own the SD Keyring but borrowed a friend's Mini eGo for a week and I found pros and cons for both:
Pros
SD Keyring is auto so when stealth vaping, which is why I bought it, no light comes on.
eGo Mini is a larger batt.
eGo Mini is manual so less chance of juice damage and user can control vape.
Cons
SD is auto so there's a chance of damage from juice. SD is a smaller battery and has a 5 sec cutoff.
eGo Mini is manual and button light goes on when activated "if" you're looking for true stealth.
Overall they both are amazing PVs and, surprisingly, very powerful. If you're not looking for a true stealth PV the eGo at $12 is a no brainer considering the SD sells for $20? Just seems the eGo is more bang for the buck IMO.
The only reason I bought mine was to use at concerts and it has served me well providing:
I have a spare PV in the car to use as soon as the concert's over.
Have to remember to vape moderately with the SD.
For other situations I could always break down my Megalodon Tube Mod to a 2 5/8" (without carto or clearo) stealth PV with an 18350/ 1200 mah 3.7 volt PV.
OKAY, You own both. Which do you prefer? You seem most qualified to make my mind up for me