PIREP of sorts: got a new headset, but should I keep it?

Okay, so I finally ponied up and purchased a ANR headset. After much
hemming and hawing over the Lightspeed 20-3G and the Flightcom Denali,
I went with the Denali, primarily because they have a 30 day money back
guarantee, and because everyone seems to get the Lightspeeds and I
wanted to be different.

So far I have flown with the Denali's twice for a total of just under 4
hours. The initial out of the box impression was that they are well
constructed. Tight seams, no loose parts, feel pretty solid. After
following their fitting instructions, the fit is firm, yet comfortable,
and after two 2 hour cross countries I have felt no pain or pressure.
At 13.4 oz they are light enough, although they feel like they sit low
on the left side, which is where the mic boom is, and I haven't been
able to adjust that away yet. I suspect that the cord is stiff in it's
new-ness and is pulling it down.

As for noise attenuation: I have been flying for over a year with a
cheap $99 Cobra headset, and I expected to be absolutely blown away
when I put these on - it didn't happen. The passive cancellation is
actually not as good as the el-cheapo set. When I flip the switch, it's
better, and it definitely cancels the low frequency noise, but the
higher frequencies are right there. I wouldn't say it's loud, per se,
but I guess I expected the "I turned them on and thought the engine
quit" effect that I've read about so many times with various ANR
headsets. Funny, but in flight, it kind of sounds like the default King
Air in flight simulator (which I think sounds more whiny than the real
thing, at least in the cabin). A quick look at the groundspeed on my
GPS confirms that I am, in fact, in a Cessna 152.

In all this, I guess my question is, is there an ANR model that will
really blow you away, or is my experience par for the course at $500?
Should I go Lightspeed? The 20-3G does claim an additional 3-4db of
cancellation, but the frequency response curve is almost the same. Does
even the mighty Bose X have the "engine quit" effect?

John K.
PP-ASEL
Student IA