Theres another thread with basicaly the same discussion. Every single had out there has the possibility of leaking. Just take your time and put it in carefully. The modquad is one piece, uses stock studs, has alot less orings than pro design and mabey others. Has 33% more coolant capacity and PD, and Noss domes will work with it as well. Its really all a matter of opinion. Theres no PROOF that one is better than the other. I'll get you a smokin deal on a complete Modquad setup if you want one. Or any of the other ones out there.
I can have the MODQUAD ones engraved with my shop name or anything else you would like. With My logo no extra charge. With yours its a $25 fee. $ colors to choose. Billet, black, red or blue. If your interested in one shoot me a pm.