I will be in a position to upgrade next year. Is the Z518c or L worth it or just go with the Z520. I would buy a new Z518L or a two year old Z520. What's the better way to go and why? I fish small, medium and larger lakes. Lakes like Douglas in Tn, Guntersville, AL, lake Mitchell, AL, lake Norman, NC. I've had my old 17 foot Ranger on lake Erie inv3 footers. Just cant go very fast and was occasionally getting water over the bow. Usually dont fish the great lakes though.