After buying my Epiphone LP Special P90, I decided to do a pick-up upgrade because the Epiphone PUP's were a bit muddy. A friend of mine recommended the the Seymour Duncan SP90's, but which ones? After researching the Duncan Website I decided on the SP90-3B Custom at the Bridge position and the "Vintage" SP90-1N at the neck (other review) for maximum flexibility.
The fitting of the pickup in my Epiphone was absolutely no problem, just had to do a bit of re-wiring and, so if you are handy with a soldering-iron you should have no trouble at all.
The sound of my Epiphone at the Bridge is pretty compressed with a lot of power! (rated at extreme output by Duncan), the sound spectrum goes from almost twangy to full blown metal and really smokes the stock Epiphone PUP's, not the slightest hint of muddiness and really open:-). If you need a good "High Powered" P90 Upgrade then this PUP is for you.
Cheers