Mark of shadow, worth it?

[Yuukale]

Folks, I'm running LDB's shoot to thrill (http://community.wizards.com/go/thread/view/75882/26335941/Shoot_to_Thrill) but ain't getting the defense boosters because our DM NEVER targets me and when he does, its always with 5-6-levels-above-bosses (meaning defenses are nigh-useless).

Point is: I have room in my build for other feats. Do you think that Mark of Shadow is worth it? Our DM houseruled that 1/day we get to use a ritual without expending gold and material comps.

Damage-wise there's nothing else to grab without fundamentally altering my build (or so I believe). So, out of combat, is there a more useful feat than Mark of Shadow?

[Surrealistik]

It's worth it for Phiarlan Phantasmist at least.

[Yuukale]

I'm a L14 Battlefield Archer. Any other PP is out of question :/

Currently, my feats are:

L1 - Weapon Proficiency (Greatbow) (PHB)
L2 - Weapon Focus (Bows) (PHB) - Retrained into Icy Heart at L11
L4 - Bow Expertise (HotFL)
L6 - Sneak of Shadows (PHB)
L8 - Treetop Sniper (MP 2)
L11 - Lasting Frost (PHB)
L11 - Wintertouched (PHB)
L12 - Novice Power (Snap Shot) (PHB)
L14 - Don't know yet

There's Called Shot if I follow LDB's build, but this is my only chance to get Mark of Shadows if I want to (Long story short: I'm not from eberron, but I went there and may get it if I so choose until tomorrow)

So, outside of the combat feats (which I will pick up anyway since I won't get Improved defenses or epic fortitude), what do you suggest?

[neonchameleon]

How much do you hide? Do you rely on CA from hiding? How often do you miss? It's a useful feat but doesn't feel like the right feat for a make-them-fight-in-the-shade Battlefield Archer.

[vasharanpaladin]

If you are not taking Phiarlan Phantasmist or Thuranni Shadow-Killer, Mark of Shadow is NEVER worth it.