I’ve done both maxxed and pair them with BT and Wilbur in raids for a 4-1 stack. If they all fire at the same time (not that difficult), it’s over.
I like them both; it just depends on if you prefer the riposte or the fire ball (and that may be moot if the other side lacks dispellers). Elena may be preferable on a Titan, but both have value in my book.