Mika,
 
The more limber the rod, the more it acts like a shock absorber.  If you are used to a faster rod, i.e. more backbone, it can feel kinda strange until you get used to it.  I personally like a rod with backbone, but the limitation there is if the fish suddenly takes off and you don't have the drag set properly, the tippet can break.  The sudden shocks are what usually break you off. 
 
One thing we have not considered is the amount of flexibility of the leader material or tippet.  Some lines have no flexibility at all and others give quite a bit.  I wonder how much this makes a difference in people's perception of the leader material?  Think about it.  If you have a slow action rod with a flexible leader, there is a lot of give so quite a bit of the shock the fish puts on the line during the fight is taken up by the leader and rod.  If on the other hand you have a really inflexible leader and tippet material and fast action rod, the drag on the reel needs to absorb the shock.  If the drag is not up to the challenge, then you may have more problems.
 
Of course, there is the tinsel strength of the leader material, abrasion resistance, how long you have been fishing it, small nicks and cuts and the uncanny ability of steelies to run around rocks, over sharp ledges, and behind logs, all of which will push any leader or tippet material to the breaking point.

Fluro vanishes under water until it gets knicked up. It doesnt stretch, costs more, and doesnt float.

Fluoro line is thinner, yet stronger.  It creates a far better presentation than a thicker line.  The thicker the line, the less movement your fly/bait has.  You're presentation should flow with the water, not cut through it.  Afterall, presentation is what it is all about.  Not line color.

You can get a fish in pretty quick with a 10' noodle rod (with a small amount of backbone) and a good 4 lb. line with side pressure and backing them in.  Another thing not mentioned yet (unless I missed it):  I would rather cast light offerings with the 4 #.
 
[seejib:  I definitely looked like an idiot when I went steelheading the first time.  I was still new to fly fishing and had to false cast to get any line out.  I stayed out of everyone's way, though.  Switched to the noodle rod for a while until I could roll, water-haul, etc. cast better.  It's all good, though.]

Gentlemen,
     Just an opinion for discussion.  I think the main reason some people complain about the wt of line that others are using is the fact that some anglers go way too light for the number of people they are fishing around.  I have caught steelhead on, of all things, a bamboo 4wt rod with a 4 lb tippett.  I caught it in the long hole at Girard park and I didn't interfere with anybody else because it was just me and a friend there fishing.  But it took almost 15 minutes to bring the fish to net because I was afraid of breaking the rod, or the tippett.  Now imagine me trying to do the same thing in the Manchester hole on a fine Saturday morning.  I would be cussed out from one end to the other.  (scuse me comin' up,  whoo!  watch out comin' down , whoops comin' back up, sorry comin' back down, Watch your line comin' back up!  S'cuze me comin' back down).  See! ! ! It even pizzed people off to read it let alone experience it.
      So my choice is: When I'm fishing around people 6 > 8 wt, No less than 6 lb test tippett just to be courteous.  IF and only IF I can find a place to experiment then I may go 4wt and 2 pound.  It is only a matter of being courteous to your fellow fishermen.

Well I made the transition from skiing mode to fishing mode(seperated shoulder from a crash and burn helped that out) anyway, 4lb clear Magna Thin on my 10' riversider should provide a good fight and hopefully not get anybody upset around me. I hope the tribs will reduce by Sat/Sun. I'm itchin to get some bait flyin!

8lb. Seagar carbon ice,low and clear, high and muddy,30lb. King salmon,17lb. Steelhead,  mass numbers of fish, on one line