I need things that Apple has removed from Yosemite
No.
Whilst I can't predict what will be in 10.10.5, I assume that it will not have the things that I need.
Theoretically: if I focused solely on needed features that are integral to a released version of the OS, I would probably aim for OS X 10.9.4.
Realistically: I want more than is integral to any release of the OS and these wants include ZFS with support for Spotlight so I'm aiming for OS X 10.8.5 and tuned use of ZEVO.
Will you really need Yosemite?
No.
Will 10.10.5 be better than 10.9.5? If not, I'll be sticking with 10.9.5!
Whilst I can't predict what will be in 10.10.5, I assume that it will not have the things that I need.
Theoretically: if I focused solely on needed features that are integral to a released version of the OS, I would probably aim for OS X 10.9.4.
Realistically: I want more than is integral to any release of the OS and these wants include ZFS with support for Spotlight so I'm aiming for OS X 10.8.5 and tuned use of ZEVO.