TarMK versus MongoMK... trying to decide recommendation

Folks,

I've been doing some research on AEM 6.0 implementations and I've learned a lot by searching and reading in the forums. I'm trying to determine whether to recommend TarMK or MongoMK for a new installation. I understand the former is aimed at performance and the latter is aimed at scaling but where to draw the line between the two remains elusive. I understand it depends on content size, complexity and performance of the individual nodes but I wonder if I'm clearly over the line in terms of scaling and should drop TarMK altogether?

Any experience or links to 'official' adobe guidelines would be greatly appreciated, docs.adobe.com isn't giving me much in terms of hard data!

Specs:

- AEM 6.0

- about 200K visitors/day and about 10M page hits per day

- Probably about 1,000 pages to start growing to 10,000 over a few years

- Don't know if there's any user-generated content

- Client can tolerate outages on Author nodes but will implement some form of high(er) availability and site contingency