I like to hide the butter under the steak, that way it marrys with the juices from the steak and becomes part of it.
It also helps save your @$$ when you've (gulp, God forbid) over cooked a steak and you're worried about it's juiciness... it may not be as red/pink as they wanted, but as long as it's not dried out there's usually not a complaint filed against you.
You should try Patio Daddio's heavy salted method (can't recommend the wooster sauce idea he has) it makes for a fantastic steak!! I do a very similar thing with salmon fillets to lock in the juices.
http://www.patiodaddiobbq.com/2009/02/steak-average-to-awesome.html
I recommend adding some herbs to the salt party and then after the rinse adding some simple herbs & spices like rosemary, fresh cracked pepper, crushed red pepper (if you like it a bit spicy) and dried garlic granuals or dry minced garlic. Let it all sit for about 10 min for the moisture in the beef to activate the herbs/spices and allow the meat to come closer to room temp (helps achieve a warmer med rare on thick steaks)
Preheat your plates with hot tap water to keep the steak hotter for longer.
Pop a pad of budda' under that sucker when it's done and watch the crowd go wild!:clap2: