Blissey is usually used as the special defense wall on a team. If that's the purpose she's serving for you (and not Heal Belling, special attacking, serene gracing, etc), then I'd say sure, think about a switch. :)
I mean, your team looks cut out for Sandstorm! Tyranitar's automatic sand stream, metagross, flygon, and shuckle all take it (or actually benefit from it), but Blissey is hurt by it (completely negates leftovers or causes mucho damage to Blissey's large HP). Shuckle should be a particularly good tanking substitute for Blissey here because during a sandstorm in D/P, his amazing special defense is
raised by another 50% due to his Rock typing! Plus, he gets Sturdy which prevents 1-hit-KO moves people nowadays are using against my Blissbliss to get around its tankiness.
So for sheer tankiness, an equal if not better special tanking ability (unless they use tons of hydro pumps), plus a much better physical walling ability, plus immunity to OHKOs, plus an asset to a sandstorm team, really means you might consider switching Blissey for a super special attacker or something. Maybe something that could turn you into an even more heavy-duty sandstorm team :)
PS:
is using choice bands really popular?
where can you get them in d/p anyway?
Where I'm from, people can't get away from them :) They tend to load the battle tower with them, too. And...it's not just choice band :)
1. Choice Band--gives anybody who wears it an extra 50% Attack at the expense of sticking to the move you used over and over until a switch. Yes, actual Attack is boosted, so the wearer's special attacks aren't. Snag this thing at the...dumdumdum...BATTLE TOWER! For, like, 48BP (it ain't cheap).
2. Choice Specs--gives anybody who wears it an extra 50% SPECIAL Attack at the expense of sticking to the move you used over and over until a switch. Yes, actual SPECIAL Attack is boosted, so the wearer's physical attacks aren't. This thing you can pick up in Celestic town in that Fake pokemart (you know, the one in the house instead of the blue MART). There's some glasses guy who gives it to you really, really early in the morning.
3. Choice Scarf--the KILLER ITEM OF DEATH. Woo, this thing boosts speed 50%. That's...a tremendous advantage. A Garchomp with one of these on gets up to ~500 speed. That really sucks...especially if you counted on some speedy pokemon to finish it off in a jiffy. You could give one of these hot things to your Flygon and his speed would skyrocket, making it faster than any respectable Crobat or even electrode or ninjask. That can really mess up your opponents, especially since the fastest Pokemon on your team is Flygon (unless your metagross knows agility or your Dragonite really Dances). Battle tower for this one, too, I believe.
PPS: That's a long PS... ;)
