Never heard the LPs, but the S500s got really good extended highs that is not fatiguing and their sub bass does pretty deep along with a good amount of mid bass that doesn't bleed much into the mids or highs. Nothing on them sounds recessed but they have more emphasis on the lows and highs that's for sure.
If you are not on a budget, you should check out the ATH WS99s. A true audiophile basshead can done right without a doubt. The bass is so deep, clean and solid that it can literally rattle the ear cups like this... without affecting the mids or highs. I would say these are a total upgrade to the S500s and then some esp. for the bass quantity.
Hope this helps. The S500s should sound much more musical and more balanced that the LPs from what i have read. Those LPs seems to be just a one trick pony, with it's crazy bassy dark sound signature.