Currently I have 2 large V7000's. When running 6 LTO drives I can push them to about 2GBps and 6K iops. not bad for 7200 RPM disks

Now that I am due for a full hardware refresh I'm considering the following.
Exagrids at both sites (Not sure if the performance is going to be great)
Pure or IBM flash at the main site replicated to an Exagrid at the DR site via COPY job (not sure if this is ideal)
Perhaps a mix of Flash at the main site and some hybrid solution for retention at the DR site.
Both sites have tape libraries and will stream the backup jobs to tape.
I basically need to hit at least 2GBps to not degrade my current window, but hitting 3 would be better.
Anyone with Exagrid's or Pure Flashblades, what kindof speeds can you hit on your SANS?
I'll add I have a ton of data. I need to be able to either restore, or instant restore 100's of TB's and hopefully not have it become inaccessible. (This is the appealing reason of flash)
Budget isn't really an issue, but I'd like to keep it as low as I can. The Exagrid solution is cheap, but I'd love to see some real numbers posted from people.
Thanks