Location of compoments.

"Normally I can close my eyes and hear the shape of the rack in between"…

Well, okay then (sounds like good clean fun-;).

DeKay

I have a weird shaped room and between that and space considerations, having the rack between the speakers is my best option, but it's a compromise. I have a nice solid center image, good imaging, and a big soundstage, but it's easy to tell it could be better.  I set up a pair of speakers to demo for a sale recently out in front of the speakers I'm keeping and the imaging was more precise and the soundstage had more depth. 

@whart: We’re suppose to listen to your opinion on hi-fi sound when you have a Marshall amp rather than a Fender? Just kidding, unless you have a Charvel guitar plugged into your amp. A Les Paul is marginal, but since I love AC/DC I guess I have to accept a Gibson SG. One combination I've never seen or heard is a Telecaster (my favorite electric guitar) paired with a Marshall. But I can imagine Brad Paisley playing that combo.

As for racks, I prefer a 34C, pear shaped please. And capped with puffies.

It is preferable not to have racks between the speakers - mainly on account of diffraction. However provided the rack is even a little behind the plane of the speakers, it's not an absolute disaster. Sometimes, as in my own case, there is simply nowhere else in the room to locate the equipment.

@bdp24 - Pete Townshend played his Tele with Marshalls in the '60s. And Jimmy Page may well have as well. But then, the JTM 45 is a hot rodded Bassman anyway so there is Leo Fender DNA in Marshalls anyway.

@yoyoyaya: Townshend played a Tele in the 60's? That I did not know. I saw The Who in '68 and '69 (fantastic!), and neither time was he playing a Tele. In '68 he was still smashing his guitar to end the set, and there is no way to break a Fender guitar.