I was not a fan of the McLeod RST. When I bought it, it was marketed to hold 800 hp. A couple years later, they add a disclaimer in the description that it is not suitable for racing and I found that out the hard way. The discs heat up and you will not be able to shift at all until it cools down. I never had issues like that with an Exedy Mach 500. The Mach 500 is stiffer than stock but you are used to it in about a week. It held up to a stock motor, single turbo car at the track with drag radials.
If you do want to go to a McLeod dual disc, go right for the RXT. The drivability is barely different than the RST and it can take the heat. The RST is strictly for the guy with a GT500 who wants something better than stock but drives it like he's afraid to hurt its resale value.