As someone who has Estelle on DMM (and got her with 8 rolls on nutaku) i can say that Estelle is quite incredible. Deploying her means brutally murdering your enemies in an inferno of doom. She's the reason i could clear phalanx 2 so insanely early on DMM because i just deployed her in the last few seconds and smashed everything to pieces.

All in all, she makes a ton of maps rather trivial and her 2 min SAW just is the cherry on the top.