Piece of mind is a term tossed around here. Of course, the bias is to err on the side of caution, and over-do any beneficial maintenance. However, the goal is to use a rational approach, with cost-effectiveness being a good metric.
Expensive or fancy sounding oils may not offer anything over a known-good 5w-40 like Rotella T Synth, that's a fact. Being able to change the RTS twice as often for the same cost is a fact too. Therefore, running the RTS at a shorter interval is a better approach at the same cost, because surely fresh RTS is better than Motul or Elf after 5000-6000 miles.
Change interval is another area of "compromise". Of course 1000 miles is too short, and 10k is too long considering it's only $50 worth of oil. That in mind, you can see that expensive oils have little merit, even extended drains to justify the cost makes little sense.
Back to M1 HM, it may actually be one of the best oils on the market. I'd try a fill of it and use the saved money for a UOA. Few here would argue that's an ineffective approach.
Just as the use and acceptance of 5w-40 Euro oils is catching on here, Euro oils are going thinner, to 5w-30, which we have a wide availability of. I have light Edge 5w-30 in my new VW turbo, and will do a UOA. If wear looks good, I have a winner, because I got 15q free, and it's cheap anyway. Lower HT/HS than spec, but it has an excellent track record in Euro engines.
So, if the question is what's the best oil for your car, M1 HM should be as good or better than anything. It's formula is unencumbered by API SM or Euro low-saps additive limits. HT/HS of the 10w-30 is beyond the 3.5cP VW specs call for and the same as heavier 5w-40 oils. That's the mark of a premium oil, high HT/HS for the +100c visc. Redline and German Syntec offer this. The HT/HS of M1 10w-40 is 4.1cP.
http://www.mobil.com/USA-English/Lubes/PDS/NAXXENPVLMOMobil_1_High_Mileage_Oil.aspx
I would go with the 10w-30 for winter and top-off with 10w-40, the reverse in summer.
