I am in the process of installing 20x 255 watt suniva panels on my south facing roof.
I am going with a single sunnyboy inverter for the following reasons:
1. Keep it simple stupid. More gear is more chance for breaking.
2. My roof gets good sun without shading
3. I am trying to do this as easily to install, maintain and as low cost as possible while purchasing good parts.
4. I will be installing off this myself with help from dad, who is licensed electrician in my state.
5. Nothing proprietary
All said and done, I will have a 5kw system for just over $5 grand installed.
This is before the 30% federal rebate, which will take it down to $3500. At this price, it will pay for itself in 3 years max.
It is all about perspective.