I expect digging around the archives could lead you to a respectable body of opinion, especially if you widen your search to include other ML models which have similar minimum impedance levels.
The argument of zero negative feedback and Class A are also in the archives (with lots of contribution from the aforementioned Ralph, a respected designer who also makes for an interesting read when he gets involved in a thread). Long story short, I expect a great deal of the result of using one, both, or neither attribute successfully is about implementation, not about inherent characteristics.
And with regard to the 5 watts, unless you listen to thrash metal or bass drums constantly, the vast majority (in terms of minutes listened) of what you listen to will probably not exceed a 5 watt pull, it's just that some of it will, and when it does, it will exceed that by a long way, so yes, you need more wattage than that.
The argument of zero negative feedback and Class A are also in the archives (with lots of contribution from the aforementioned Ralph, a respected designer who also makes for an interesting read when he gets involved in a thread). Long story short, I expect a great deal of the result of using one, both, or neither attribute successfully is about implementation, not about inherent characteristics.
And with regard to the 5 watts, unless you listen to thrash metal or bass drums constantly, the vast majority (in terms of minutes listened) of what you listen to will probably not exceed a 5 watt pull, it's just that some of it will, and when it does, it will exceed that by a long way, so yes, you need more wattage than that.