Hmmm...I tried some heavy, very heavy trout streamers on the 6 weight...does it, and does it well using a spey/role cast, BUT, normally when Pike fishing you retrieve to your feet rather than having a length of line out and spey/rolling from a distance.
Many Pike take within a rod length and it is important to get that fly in close. Spey casting you lose 30 feet of retrieve.
I am now using a Cortland Rocket Taper Pike fly line, which is rather good. I also have Rio Outbounds in Intermediate and Slow sink and shooting heads in float, slow and fast sink.
I use the Cortland for 90% of my fishing.
So, although the SLX will deliver the flies, I just think its development as a spey line means its limited for stillwater Pike.