The M149 would not be comparable to the FET mics, as it is a tube mic, and closer in design to the L47MP, both of which attempt to emulate a U47.
It's interesting that you mention the M149, because indirectly, that's how I happened to buy my L47mp.
A few years ago, when the M149 was brand new, i was at the AES show in NYC specifically looking to research getting a "go to" vocal mic. Up to that point, my best vocal mics were
a TLM 193 and a 414b/ULS.
When I heard the Neumann M149 at the show, I fell in love with it. And, of course, went into an immediate depression because at the time it was listing around $4900 (if i recall) which meant I was going to have to drop around 4 grand on the street. Unfortunately, nothing else at the time (like at the Rode or other mic booths) gave me even a fraction of the same thrill, so I was resolved that i was going to have to live on laundry starch and dog food for a while.
Just as i thought I had seen all there was to see, i stumbled upon Gene Lawson in the very last aisle of the hall. I had never heard of his mics before, and he didn't even have one hooked up to try. But he had a CD for me to listen to which A-B'd the L47 with various other mics in various applications (like a U87 in a voiceover situation, e.g.). Even with my naturally healthy skepticism I was impressed.
Gene agreed that if i ordered one, i could keep it for a week or two and try it out against other mics and return it without questions if i wasn't thrilled with it. In fact, I was thrilled. I got my "M149" sound at 1/2 the price ($2000).
I use it on male and female vocals constantly, but like the U47, if you had to pick the "perfect" application, it would probably be certain male vocals. But a lot of VERY picky pro singers of both sexes who have used it in my studio love it. I've also used it with great success on acoustic guitar, guitar amps, acoustic bass, woodwinds (including flute), and strings. I've even used it on chromatic harmonica (about 12" away, not hand-held blues harp style). Where I wouldn't use it? Definitely not on jangly high percussion like triangles and tambourines. Unless it was from a good distance. But then, a lot of great mics sound crappy when you get to close to jangly things.
Nowadays the decision between the L47mp and the M149 isn't quite as clear-cut, as Neumann has slashed their list prices. I believe you can find street prices on the M149 under $3000 now. But it's still going to be $600-$700 more than the Lawson, and I'm not sure you're getting a better mic.
I have seen a few people post on various bulletin boards that they were not impressed with the Lawson. It's hard to see why, since in this studio it gets close to unanimous raves from the artists. But perhaps it could be an issue of matching with the right preamp. Most of the time I'm going through
a TubeTech MP-1A, but for a different sound will use anything from an API to a Daking. Perhaps the preamps the dissatisfied posters were using were not a good match.
