Unfortunately they also have a habit of doing things in too much of a hurry, such as leaving fluid levels low (possibly from not letting bubbles settle out), misaligning hubcaps, and using incorrect (low) tire pressures. The last of which helps fulfill their goal of wearing out tires sooner so they can pitch replacements. This is sort of a risk with most garages, though.
The schedule on my leased vehicle is stretched out further per oil change than a local garage suggests (15,000km vs 5,000km).
I've never had an oil-related failure.
And before you ask, yes, they're all high-mileage; for a while I was doing 25,000 miles/year.
However, it is great for people who wants to work on their own car and resell value isn't really a concern.
Adam saruwatari on youtube shows it in action.
Willing to risk destroying the car to save hundreds of dollars.
I don't get it. Those two things seem incompatible to me. Ferrari isn't about frugality, and cost of ownership necessarily means hundreds of dollars is not a problematic expense.
I've had bad luck with independent mechanics taking on jobs they weren't capable of doing properly and ruining a car in the past. Although it sounds like you had an honest one, independent mechanics aren't necessarily above selling you goods and services that you don't need, especially if you don't know the maintenance schedule or have maintenance records.