RPi3 upgrade questions

[superczar]

I have had Domoticz running in production for around 1.5 years now
I upgraded from a Rpi B+ to a RPi2 around a year ago and found a massive improvement in responsiveness
The upgrade was also near seamless as I simply installed domoticz fresh on a new card and copied the existing domoticz folder including the DB and custom scripts

Now I am wondering if I should make the switch from Rpi2 to Rpi3 and have a few questions for those who have done this already

a) Should i use the 32 bit or 64 bit domoticz ARM image?
b) Is there any discernible improvement you saw post the upgrade
c) was the transition seamless and simple?

[gizmocuz]

a) is there a 64bit version ? Can you give me the url ?
b) Its a bit faster... not so shocking