I have canon EF gear ; 1dx2 , canon 600 is 2 , 400 do and 180 mm
I was inactive for many years and now i m planning to be take photos again , at some point i will get mirrorless systems sure ( may be in 1-2 years ), so the question is after leaving dslr system , should i go another brand or staying on canon with EF/RF converter ?
also is the lag of canon at producing tele lenses behind nikon sony means anything as may be canon will give priority to cine systems ...
The easy part of this is that using an EF/RF converter converter will save you a lot of funds and then you can see how your existing lenses proform and chose which if any to replace.
There are fans of every system and they will all tell you theres is best. That's because all of the high end gear is extremely capable. There are some stand out lenses from each brand and if you are looking to change I'd pay special attention to the ones in the focal lengths that you do most of your work in.
Also, pay special attention to ergonomics as this will have a major effect on how much you enjoy using your gear. No review can tell you which you will like, try each body you are considering in a store and then rent your top choice(s).