Mahler vs. Strauss

I find that the sound picture of Mahler’s orchestration is more effectively produced in stereo recording than that of Richard Strauss. I think both are superlative orchestrators, but somehow Mahler’s symphonies image better than Strauss’s tone poems on my system. They seem to be fuller, fill the sound stage more effectively, and are easier to reproduce. Not that in any way they sound “bad.” They sound fine, but Mahler’s orchestration seems more effective.
Does anyone else have that impression?
Recorded in the same hall by the same orchestra? Same label? Or just in general. IME there is certainly a  lot more Mahler to choose from, ergo more great recordings. BTW, just sound wise, Schwarz and the Seattle SO has some excellent recordings of Strauss, Wagner, and other American composers on Delos. FWIW.
My view of Strauss' music is that it is more of a simplistic, romantic music, that you can easily hum along with, or in you head without, a recording. Much like Tchaikovsky, only more developed and interesting (to me). As such when you are listening to your stereo system you are hearing a focused tune, one that comes from more from the center.

Mahler, not so much. Even though you might be very familiar with it it is not music that lends itself to easy memorization. You may know it well enuf to anticipate what is about to happen but, apart from the performance, you don't walk about humming a tune. In other words it is music that involves you.  Its not background music! The music itself goes from ethereal and quiet to loud and dramatic. Tonal to atonal and back again. Angst and shear beauty alternate.

 Bottom line, as I see it anyway, its not your stereo system so much as it is simply that you are really listening to Mahler more attentively, and quite possibly because of the drama inherent in Mahler's music, more loudly. I can't believe how loud I play the last movement of Mahler 2. :-)

FWIW, a POV from the unwashed. 
I never warmed to Richard Strauss. Even though he stated that he could describe a teaspoon through music, I find it hard to listen to. Add to that fact that he was a deadbeat and anti-Semite, I would rather concentrate on other composers.
Mahler, on the other hand, was a more 'human' composer. His later works are pretty deep, but when you open your mind, they are quite beautiful.
As far as how they reproduce on stereo systems, I would say that is listener dependent.
Mahler became a quick favorite for me during speaker auditions because of the amount of space in the soundstage -- not sure if that captures what you're hearing, but I can glimpse what makes Mahler's orchestration more demonstrative of a deep or wide soundstage. I've not done more than skim this, but possibly of interest
I have always found  symphonies, regardless of composer, are difficult to reproduces on a home stereo.  Have tended to stay with works ranging from solo, up to quintets.  Personal preference I understand, but for me the listening enjoyment is greater.  
I have not really noticed what you're obviously hearing.  I think newbee's possible explanation makes a lot of sense to me.
To be sure, there's a good deal of Richard Strauss I like.  I truly love the Four Last Songs, the opera Ariadne Auf Naxos (some utterly sublime tunes!) and at least the opening fanfare of Thus Spake Zarathustra.  But yeah, I ultimately find him a little bit pat, noisy and empty. 

By comparison, Mahler conjures up universes you can walk around in and get lost inside of.  He can take you back to the dawn of history, to the first days of our planet. His Ninth Symphony takes you forward in time to a day where the earth is a smoking, poisonous ruin. 
Interesting question! As for the music itself, the short version is that I admire Strauss, but I adore Mahler. This emotional distinction may color my judgement on the sonic differences as well, but I’ll try to be as objective as I possibly can.

According to the experts Strauss had few peers as a orchestrator. But to my ears his arrangements are often very dense and saturated, some would even say perfumed. Although I must make an exception for the expressionist Elektra, an exceptional work in every way. Somehow his music doesn’t sit well with audio reproduction in the home and the sound stage easily gets ’clogged’. However in the concert hall even his most densely orchestrated pieces work very well, perhaps because there’s simply more room for the music to breathe.

Mahlers orchestrations are usually more ventilated and the huge forces required for his symphonies are used sparingly. Apparently the home system can more easily cope with that, perhaps because it gets the opportunity to ’catch its breath’. Of course when all hell breaks loose (or the heavens burst open), no home system can ever hope to reproduce the impact it has in the concert hall. This is an experience like nothing else. Very hard to put into words, but very easy to recall. Like that one time I heard the 6th in Vienna by the VPO, especially the finale. Just thinking about it brings me the shivers.....

Interestingly, many years ago I had a totally different stereo setup, much less revealing, not as high end, but perhaps a little fuller. I had two small speakers in the rear of the room with a Lafayette device
to pick up ambient sound. It was in a smaller room than I listen in now.
On that set Strauss sounded marvelous, somehow, if not as sound staged, more imposing. It completely filled the smaller room with sound.
I miss that “Strauss room.”
I never warmed to Richard Strauss. Even though he stated that he could describe a teaspoon through music, I find it hard to listen to. Add to that fact that he was a deadbeat and anti-Semite, I would rather concentrate on other composers.

Aren’t you confusing herr Strauss with Wagner?
Strauss was apolitical and collaborated with Jewish musicians. He did not join the Nazi party, but to keep his career and family safe he did not speak out against them. Very similar situation as Furtwängler.
Strauss fell out of favour with Hitler because of his working with Jews and his daughter was married to a Jew (which I’m sure was kept secret). Strauss then spent the rest of the war with his family under house arrest.

Now, Wagner was a real dirtbag and anti semite.

To put it very briefly, their orchestrations deriving from their manner of thematic composition are very different.  Strauss, more of a Wagnerian with (relatively) simple broad themes.  Mahler is often though of as composing chamber music for his large orchestra.