Stuart
With an E/W split, it makes sense to install on both roofs to spread the generation, perhaps with a slight bias to one side (if either) faces slightly closer to south.
There may be an argument to skew the generation in favour of west-facing as more power is used in the afternoon and evening rather than the morning but this really depends on the household.
We only suggest optimisers when their is shading and/or we are installing on 3 (or more) roof surfaces as in your case.
Additionally, speaking from experience I know that if I go to see a potential client and they are from a technical, electronics, electrical or engineering background then nine times out of ten they pay the extra for the micro inverters.
For them its a combination of the stand alone aspect of each panel, the much reduce electronics in the micros, the lack of a DC cable in the house, the longer working life, and of course the real time monitoring of each individual panel. IF you are from a technical background you will love the level of information you get.
Hope this helps.