Hi John
Seraphim is a decent panel for what it’s worth.
Let me challenge your goal of finding a highly efficient panel. Have you got limited space on your roof? Really the only reason efficiency in a panel is important is if you have limited space (same output in a smaller panel). Otherwise, it’s build quality that is what really matters. In reality the two often go hand in hand, but I wouldn’t rule out panels simply because they aren’t super high efficiency, especially if you are also on a budget.
If you’re on a budget, I would personally be looking at a Sungrow inverter and either, Trina, Jinko, Canadian or LONGi panels.
Hope that helps.