Female Morgan +res -spd glacies vs iceberg?

I mean,, if you're desperate for "burst" damage, then Glacies.

However, if you're fine with her current damage output and wouldn't mind lowering her damage output, then Iceberg

Glacies if you expect to be doubled, Iceberg otherwise.

I have a -Spd/+Res one so even with flier buffs, I can expect to get doubled so in that case, I would run Glacies. At neutral spd or boon, Iceberg will probably do better. You can prevent most units from doubling but you can still double with QR so that's enough to trigger Iceberg.