I am just not particularly trying to argue the merits of an ME analysis vs. someone's opinion on how well a particular part works. While first hand knowledge is great, the statement "the NVH wasn't too bad" is a totally subjective statement and could be true or false depending on who you ask. The solution of course is to try that part out yourself, but its hard to justify spending money on different mounts just to see which one you like. So we come to my statement, it was just meant to be an informative statement on what to expect from the part. And it sounds from your conclusion (...I see the RT mount for competition use (I believe he states that directly) that my analysis is correct. The NVH is probably not bearable for a car that sees autocrossing/track use and street use. Although I would like to make note here, that Eric is def. not stating that its for competition use only. He has compared it to the MMR mount and said its lower in NVH. Plus some good word choice IMPLIES (to me) that he thinks it would work well for street use (read yourself and pull your own conclusions:
http://clubroadster.net/vb_forum/showthread.php?t=37187&page=2).
Now onto the next thing, you said if you wanted a mount that absorbed vibration you would stick with OEM/MS mounts...well I want the in between here. I want to be able to track my car (I personally don't care much about noise and harness really, I just want my car stay in one piece and have fully functional gauges) and street it at the same time. I did the same thing in the MS3, poly engine and transmission mounts, It vibrated like mad...I liked it, but everything still functioned and my car didn't fall apart).
Through-Bolt design:
Let me go ahead and say this, you are practically buying a few grade 8 bits and the poly for looks. Why spend 80 bucks on that? Especially knowing that your mostly pay for the poly and it doesnt do much?
Also, consider the fact that poly stock especially in large quantity is pretty cheap. I am not going to post costs and what not, but I can tell you that someone along the line is making bukos of money on it, and I suspect its NOT eric, and you are paying for that. If you like I did some cost calculations (including speaking with my shop's machinist) on making this mounts and the price is surprising, I will pm you it if you like...Complete with measurements from the stock mount and a link to the poly source.
If you want a mount that isn't vibration isolating, then buy a through-bolt mount or fab one up yourself, but atleast know when you buy a through-bolt mount that you are spending money ON A BOLT and some semi-functional material at best! that goes for the MMR mount too.
If you want a mount that IS vibration isolating, then well...you are kinda **** out of luck. The mazdaComps are hardly trackable and the Function 7 mounts cost $300 dollars and are made for people putting down something like 400+hp. The market hole that I want to fill is in a vibration isolating mount that is trackable (hence why I want to do a poly filled stock mount).
PS. I went and read the 2nd page post. Your description was not very accurate, he did an engine swap with the mount still attached and suspects that it caused a rip in it (with a pretty good description of why) AND said that he for sure put too much strain on it. Plus, he admitted the window weld didn't stiffen up as much as he thought it would and he also did not line up the bolt heads correctly. I don't mean to be blunt, but no one has to to be dumb about it, just improve on his design and use stronger material. The **** is window weld after all, how stiff does it need to be?