The dreaded 64bit move...

3.75 GB is the maximum 32bit can allow indeed. It also makes the system more stable. At least my MacOs on idle uses 12Gb of ram and it makes it super smooth. When you load a session it reallocates the Ram anyway.
 
if you are in 64bit and use a 32bit plugin, it pops it out of the plugin browser window and is just messy. same thing if you use 64bit plugs in 32bit reaper.

Yeah, it gets really annoying. Luckily most of my plugins are 64bit now but I still use shit like the antress suite.
 
Yes but it does work natively and there aren't a lot of 32bit only plugins left. I have quite a few now, and all the major companies are now 64bit compatible. My only complaint is the GUI is sometimes not reactive but as I said I don't see 32 bit plugins anymore.


EDIT : and to clarify, the reaper bridge is automatic, no installation requirement, it's all transparent. If a pluging is 32bit and you are using Reaper64, it will open it in a different instance (you will have a window that is not embed in the reaper window), it's a bit messier, but it's stable and works well.

In effects list windows, right click > run as > embed bridged UI > profit! :D