the weekly lockout on first Coil was removed back in patch 2.2, and an echo was added to it also, so quickest way to gear up is in first coil, with the odd piece from Syrcus tower you can get which are i100, crystal tower is i80 gear, its an upgrade sure but not really required for getting up to at least i90, also the newest 4 man dungeons drop i80 as well, so you should run those before crystal tower (24-man queues, no thanks)