I have been doing real estate photography for 2 years after 13 years of portraits.
Quick question- I have a 5D MkI. For my next camera, would you recommend mirrorless?
Yes absolutely in the last year my top recommendation for real estate photographers just getting started is the following:
Some time back Wayne Capili did a post on this bunch of gear and I've heard from many real estate photographers that are using this combination and are quite happy with it.
It's worth mentioning that since Wayne's post on the A6000 there have been two other camera bodies that have entered the market. The A6300 and the A6500. Both are more expensive than the A6000 but the new features they have are more for video than for still photography. The A6000 is still the best body in the A6xxx line for still real estate photography.