After a lot of consideration, i've pulled the trigger on a refurb 12 core 2.66 for £3.4k.
Ultimately here is my thinking;
1. i DONT want to go to Windows unless its completely necessary.
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2. With this mac I have DOUBLED my 3D rendering speed over the existing 8 core 3,1 which makes a significant difference for both short preview renders and long full res ones alike.
3. IF Apple do bring out a super new pro Mac of some sort eventually next year, all well and good, I can assess the benefits then and if necessary sell the 12 core and only lose about £1k
4. if Apple DONT bring one out, at least I will have got one of the last fastest Mac Pros they did at a really good price compared to when it came out!
5. Compared to the 'new' 12 core 2.66 which is identical bar the default 12Gb ram, I've saved £600.
Anyone think I'm nuts or is my logic sound?
Now - I have to decide whether to keep my 2,1 8 core and my 3,1 8 core under the desks as render nodes/additional workstations, or sell at least one of them on to offset against the new one!?
edit: Just added a 240Gb SSD from OWC, and 24Gb RAM from crucial, and STILL over £200 less that the 'new' 2.66!