Paul,

We have 3 x 250 W solar panels on an arch with Schottky diodes, whether its better with or without I don't know since we installed them from new.
We also rarely run the generator except when leaving / arriving in port, lifting the anchor, heating the water, solar takes care of most of our needs. 
We have 5 year old AGMS (3 banks of 4 x 6v in series with balancers) which are still performing well.

Cheers
Alan
Elyse SM437