The hard mounts will invariably stress other areas, such as inner wings etc. when I fitted mine, I torqued them up several times when fitting and when taking them off after miles few, 2 of the bolts were loose. I recommend using a decent (not the cheapest) thread locking agent or check torquing the bolts periodically.
The noise produced is actually a vibration that will have an increased wear affect, it will reduce the fatigue life of welds, hard mounted components etc, and if you do fit them, keep a weather eye on other components.
Remember if you decide to leave the well trodden standard path, expect an increased maintenance burden, periodic checks, and reduced life of other hard mounted components.
Upgrade one area, and you will eventually had to upgrade the next........
I can see the point you are making Stokeballoon, but what about the engine movement with standard mounts... surely that causes wear to other parts? While I am not an engineer, it seems to me that there is a trade-off and compromise involved whether you have a standard set-up or a modified one. Obviously VW have engineered their package to provide an acceptable driving experience for the GTI market and if thats what most people are happy with, thats fine. Also, while I am sure that the VW setup has a longer shelf life than an aftermarket modified one - although exactly to what extent I am not sure and that depends how far you want to go - the issue is not black and white because for example, you might go back to the standard mounts thus relieving stress from vibrations etc... but then reintroduing engine flex also comes with its own issues and puts stress on other parts.
VW Driver magazine have a Mk4 track car that has covered over 250,000 without major issues - until the engine blew recently
- and that is a heavily tracked car. I wonder how much longer it would have gone without the mods and 'abuse' - 300,000 miles? I can't really see that modding would reduce the shelf-life of a car from say 300,000 miles (and who really keeps their car for that long or does that many miles) to say, less than 100,000 miles which would represent a significant risk if it were the case. Also, there are many other factors involved such as care regime - a standard car would also have a reduced shelf life if not taken care of - and people who tend to modify their cars generally are more conscious about the level and quality of maintenance it recieves.
So I can understand that someone may have not personally like a mod for whatever reason, but I don't think its simple as assuming that a mod will only cause stress to the existing set-up without comparing it to the reciprocal benefits in terms of freeing other components from other types of stress. However, saying all that, I do have a bit of a gripe with people who write up before and after mod reports and do not mention the negatives that come with the package, only for you to find out when you do it yourself
