'11 Supra 21v - Stereo setup good or bad?

[OnlyButter]

Bought a used 2011 Supra 21v a couple months ago. I'm about to add a second battery, perko and iso relay, and thought I might wanna replace or add to some of the stereo components while I'm at it.

Looking for some honest input on how good (or bad) my system is, and what I might wanna replace. I'm definitely not looking to be the loudest on the lake, but I do like the bass .

Here's my system:

Head Unit: MB Quart Nautic There are actually two of these in the boat (1 in the glove compartment which is a CD changer, and the other is at the helm). http://www.mbquart.com/nautic_accessories.html

In-Boat Speakers: There are 6 Kicker in boat speakers. Not sure on the wattage, but they're the typical 5" or so circular guys.

Amp #1: Kicker DX200.4. I assume this runs the in boat speakers but haven't followed the wires just yet.
http://www.crutchfield.com/p_20611DX...200.4&skipvs=T

Amp #2: MTX TC4001 Thunder - Class D. http://outlet.crutchfield.com/S-JKfF...er-TC4001.html

Amp #3: Planet Audio AC 1600.4, 4-channel mosfet. http://www.vickersav.com/index.php?m...oducts_id=2792

Sub: Kicker L5. http://www.crutchfield.com/S-42RW0AL...-06S10L54.html

Tower Speakers: There are 4 Phoenix Gold tower speakers in Roswell cans. That's about all I know without pulling them out. Never heard of Phoenix Gold...