I loved my IB3s, they MOVED. They werent built for 3kW though. They sounded easy, unstrained, effortless. They played LOW, they played high, and everything in between. I love exaggerated 20Hz-35Hz though and I had to EQ the crap out of them to get it, and I made them stink if I played them too long.
My new subs are awesome, I can give them a lot more power and they dont stink. But they dont play as low beacuse they can't move as far. I also have these EQed the same as the IB3s and I have even less lows than I did with the IB3s.
My biggest problem is my alternator, I need to get my second one added. But, I am still after a different FR curve than what I have and having much bigger motors should give me the peak around tuning and dip around 35Hz-55Hz where these ones are just too loud at.
I need four and if the soft parts are in decent shape, I need a 2 ohm load ( so dual 4 ohm, single 2 ohm, or quad .5 ohm or quad 2 ohm)
If they need reconed then I guess it doesnt matter