I think it is a function on how fast you want to ski. Ski faster - use a stiffer ski. The gun is soft, but easy to turn.
Frankly at 220, you better get all the length you can and you could bend a stiffer ski.
Neither ski is for carving hard pack.
Try a couple of demos to see which one brings a smile to your face.
BTW - There is a lot of chat about dual mount points and macho skiers like to mount their bindings further back. However, with the width of these skis, you get pretty good float now. I prefer a balanced swing weight for the bumps. At 220 though, you could power your turns ok with a back mount by putting your weight over the front of your skis. It is all about what you are used to.
I am an old slow skier, so I use my old PR's. At 185 lbs and 185cm ski, I get lots of stability and easy turning.
I really like the way Skiing Magazine reviewed skis in the Sept 2006 issue:
K2 Seth 130/98/118:
Power 62 - Finesse 38
Speed 3.4 - Turn 2.8
Off Piste 3.0
Softish tips and more sidecut up front (than in back) make for effortless turn initiation. Most testers found it snappy and maneuverable for a big ski - ideal for chutes or tight, steep lines. Gripes - Some testers found the tail stiff and somewhat reluctant to end the turn. Props - the complete package: twin tip versatility, powderworthy dimensions, and hard snow performance. Testers take: "the real deal. Awsome at speed, sweet on hard and soft snow."
Salomon Teneighty Gun 135/101/126:
Power 41 - Finesse 59
Speed 2.8 - Turn 3.2
Off Piste 3.1
This season's Gun is quick, snappy, light and easy to throw around the trees, on steeps, or anywhere that requires quick turns. It scored second-highest in maneuverability. Gripes - Can be overpowered by larger testers. Less stable at higher speeds. Props - Great for lighter skiers wanting a versitile, powder-oriented ski, or for anyone who regularly skis tight trees. Testers Take: "Worked well in all terrain, easy to flex, yet stable."