To summarize arguments:
v7:
+ can receive updates and bug fixes (unless dracolich will be sent to the front ofc)
+ more dynamic (but thats not + for some players)
+ more quality of life: you get free courier, hotkeys, overlay with heroes ulti cds and respawn timers
- hard to get used to for some players
- still has some bugs but much less than v6 (only necro bug is serious, other mostly cosmetic)
- some heroes not balanced: magina
v6:
+ less dynamic but higher demand for stratetic thinking: you lose more gold when you die, slower respawn, harder to farm which makes you think before making a move and generally play more carefully
+ convenient because you are used to it
- will probably never be updated
- has serious bugs like riki, tuskar, spectre
- some heroes not balanced: tuskar (because of bug), visage, leoric
Ofc v6 is played more often and v7 almost never but its funny how fast people forget things. Few years ago when the map was updated from icefrogs 6.73 i think to newest dracolich map everybody was crying about new map being shit too and that its dota 2 copy and that they will stop playing cuz server dead now.