What do you think about split Sorc/Bard. Currently i am testing Sorc2/Bard2 and i am planning to split up to Sorc16/Bard4 to reach tier 4 in spellsinger PrE. I can also boost Spellcraft (bard has many skill points), UMD (bard's class skill) and receive one USP per every point spend in spellsinger. I can also take wand and scroll mastery which is missing in the savant trees.
I am only worry about DC, because as Sorc16 i cannot reach highest (9) level of spells and i will loose +2 DC and MCL on selected savant tree. I can take Spellsinger's Violet Marigold Crown (+1 DC evocation) but only if it stacks with Savant's evocation focus.