opinions of glyph of FFB v Glyph of frostbolt

Sort of torn on this choice (for pvp, by the way)

let me start by saying that I've one point in Frostfire Orb, as it adds a spammable snare for fighting things like Feral druids (i play a feral aswell, obviously, so I know how spam snares are extremely effective against Fdruids)

I know that Gylph of Frostbolt pairs up well with Peircing Chill and Shatter,

However I feel that Glyph of Frostfire bolt, while adding substantial damage to the ability, kind of has a large downside in that it removes the 60percent snare on it (1p Frostfire orb) and I'm wondering what other mages have decided on and why, and what they've found to be better for the two.

Thanks,
Bamp
running Icelance and Cone of Cold, this is for frost pvp, as mentioned.
You would actually not use both of those in PvE either.
cone of cold hits for like 2.8, why trade 5% crit fb or 15% damage ffb for an extra 700 damage.