One portal on server Unix and Windows servers?

EP Gurus:

We have a EP7 (JAVA only and on AIX ) with 10 K users. It is very slow.

To improve the performance, we plan to add several DIs (JAVA only and on Windows NT) to the EP on CI.

So the landscape would be:

Web Dispatcher -

EP7 (CI + several DI) on Unix and Windows -

ECC

Any pros and cons on this design?

Points guaranteed. Thanks!