Is this a good trade?

i havent heard the RD audio subwoofers.. but i know the kicker comps dont sound very good unless they are up loud with a strong amplifier that doesnt have much distortion.

strong amplifer means two things:
1. clean power
2. faster than usual slew rate

if you feed the kickers muddy output, they will sound muddy.
but if you feed the subs abnormal amounts of clean output, they dont sound muddy anymore.. instead they sound stubborn.

when the speakers are already capable of producing high amounts of sound quality, you can still add an amplifier that has some distortion (not to be confused with clipping)
those sound quality speakers will still prove to be sound quality speakers.
it takes a whole lot of muddy power to make sound quality speakers sound like muddy junk.
and
it takes a whole lot of clean power to make the muddy kickers sound like they are more than flea market junk.

to be fully honest,
i think the 15 inch version of the kicker comps sound better than the 12 inch version.
its like all that extra cone makes the details heard.
i think maybe its because the voice coil in the 12 inch version is actually supposed to be used with a larger cone.

What are you trading? The RD's or the Kickers?

All things being equal, the 15" sub is generally louder than a 10" sub (stupid laws of physics!)

Not going to argue with Mr. Anywaypasible, but I disagree with quite a bit of what he is saying. At least in the context he is putting it.

Subwoofers performance is entirely dependent on the enclosure they are mounted in. A bad enclosure design can make a 1000 dollar sub sound worse than a good design and a 20 dollar walmart sub that you bought third hand at a flea market.

As for amplifiers, today even off brands can be decent as long as you are running them within their true power capabilities and you feed them enough power from your electrical system. The planet audio amp should do fine. As we don't know the model number to determine what the amp can actually do or if it is stable to drive your subs, as long as you keep it within its capabilities it should survive and give you plenty of good bass.

If you are trading to get the 15's, remember that they are going to require a bigger enclosure than 10" subs.

Agree with cubdenno about needing the right quality of enclosure.

doesnt sound too shabby mate!