Huge, huge longtime RCHP fan here.
It's funny how many people say "I like Mother's Milk." Because the Chili Peppers will admit that it's a MESS of an album. The producer was really making them try to sound like something they're not. Trying to make them sound like a funk-metal band, instead of a funk-rock band. I think Mike Beinhorn was the producer. And they say that they hated working with him. That album sounds like complete ass. The drum triggers, the bass is buried and EQd terribly, the guitars just kinda sound eh.
Now, Blood Sugar Sex Magic is, and will always be, a masterpiece. For them, that's the album they have yet to beat again. I think alot of it had to do with Brendan Obrien behind the board. Sonically, its just superb. Totally organic, totally huge sounding, and totally in your face. Vintage equipment, simple stuff, a few mics, some heavy handed yet subtle compression, and some really good ears. That song is proof positive what great vintage analog equipment can sound like on tape. I also enjoyed how the guitar is more of an accompanying instrument in the mix.
Californication is a sonic nightmare. It just sounds awful to my ears, next to BSSM. By the Way, again. Some weird EQ and mix things going on. Sometimes I wonder how they let stuff like that happen and go to print.
Stadium Arcadium sounds good, sonically. But at first listen, it just doesn't sound sonically exciting. I had to listen a bunch of times to figure out why. Especially to frusciante's guitar parts. At first, I thought "he's playing differently, using less gain, etc, etc..."
But for the most part, I think the BIG reason that his guitar doesn't sound as in-your-face as BSSM, is because there's almost ZERO compression on the tracks. The compression on BSSM made the funk chords absolutely SLASH thru, and cut like a knife, and the chords ring out beautifully, and all the subtle details and string sqeaks and evrything. It made it like your ear was pressed up against that marshall 4x12.
On SA, there's a SH*T ton of swirly, whirly, phasey effects going on, and reverb and whatnot. But the guitars aren't compressed as much, and to me, just sound plinky and boring most times.
Also, I feel like they mixed Stadum Arcadium backwards to how a RCHP album SHOULD be mixed. On BSSM, even if you completely took away the guitar, would still SLAM, because the bass and drums, Chad and Flea, are mixed so well and in the forefront, and the guitar is sprinkled in where it should be. the rhythm section holds that band together, and the guitars and vocals do their thing on top.
Stadium Arcadium, on the other hand, is mixed more like a "typical" rock record. Guitars upfront, and the bass supporting them. But flea's bass sounds weak as shit in the SA mix - it almost sounds like he's playing thru a guitar amp. The problem is the new double CD sounds like the Drums and bass are more of a supporting role, when in THIS band, the beauty is that they SHOULD be more in the forefront.
OK that's my rant.