I had the pleasure of purchasing a MM 3.5 Hiflow years ago for my Bavaria
It has been a bullet proof motor - over 100k miles and it still pulls strong - might be quicker then my M but unsure if Wife is giving it all - ( I win in either... LOL ) This is how my marrage works...
In short - Everthing that I have experinced with MM or have heard others say has been first class - My mechanic has had numerous conversations with MM and holds their views in the highest of regards -
I look to MM as a performance Mecca for modified BMW's - They are my choice for upgrades ( on older BMWs they are unequalled)
My conversations on topics from transmission rebuilds to rear end upgrades have always been straight and level - Even when what they told me was not what I wanted to hear - You know: after you sink money in a repair and they tell you that it would have resulted in a stronger, better repair if you had done it another way - (Note: this refers to my investigating the rebuilt tranny on my M5 - It was erronously reported to me that MM did it - MM told me that they didn't rebuildt M5 trannys anymore and would have sent an improved version of an older 5 speed that was better and less expensive)- I bought the car anyway, live with the slight gear whine in 5th gear ( turn up Radio ) and enjoy ! If the tranny ends up with a short life, MM will be the source of its replacement.
In short - If my mechanic can't do it and I want it to last its MM
- note that my mechanic makes use of MM for parts and advice so to me he is my local MM rep. -
I regret not knowing the other firm you inquired about so I can not give you an apples to apples comparision - Once I find a company that promises and deliveries - stands behind its products
and treats its customers like old friends years after a purchase, I am not straying far from the tree
1st gear .. you go faster.. Faster
2nd gear .. etc.