Pros: Small enclosures and you get the "ahhhh" factor when you show ppl you have a bunch of 8's
Cons: Don't typically hit lows very well, takes alot of them to get loud
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I ran (3) GTO804's in ~2cf tuned to 29Hz in my 300ZX last year. They were great from about 35-75Hz. The lows weren't hit with any "enthusiasm" (obviously..I mean they werent designed to) but they did great on midrange and got loud enough for me. (I say that coming from a W10GTi tuned to 28Hz)
I have a Diamond CM308D4 pending install in my current car (replacing stock sub).