U will get 20 % discount using app. Also lots of vouchers buffet complimentary , upgrades etcI have the same question. Is the Accor Plus membership worth the 4000 points (~7600 INR)? The silver ALL tier doesn't seem to have much value. Moreover, most hotels seem to offer the 10% discount over the public rate even to ALL base tier members. The red hot rooms cannot be booked using points AFAIK.
Add to it the problems so many people have reported with transferring ER points to Accor after purchasing Plus because of the membership number change.