^your Droid 3 doesn't carries a warranty or does it , and it is not brand new or is it ?? @OP needs a new phone.
Also your phone is not upgradable to Android 4 officially. [Don't mention custom ROms , most of them are unstable and have bugs.]
He wants the phone for her sister , I guess stability will be main concern.
In addition to that , the Lenovo has IPS LCD vs TFT.[ Advantage]
A much higher capacity battery.[Advantage]
ICS out of Box.
Warranty for an year.
And droid 3 was released almost an year ago , so that makes it outdated comparatively.
For a normal non-geek/non-techie user , your phone is of lesser advantage compared to Lenovo. For a performance user ,O/C droid 3.
Not want to crap your sale , but its just for clarification .
1-Motorola does not sell Droid 3 in India so no warranty in India.
2- Yes accepted no officially ICS. Not all of them.
3- Yes IPS LCD with 480 x 800 pixels resolution in 4.0 inches with 233 ppi pixel density only. In Droid3 540 x 960 pixels, 4.0 inches (~275 ppi pixel density). And IPS one type of TFT.
4- Yes higher capacity is good but depends upon consumes.
5- There is no phone in India who can run both sim cards CDMA and GSM on single sim slot with data.
6- 8 Mega pixel Cam
7- 1080p video recording @ 30 fps compare to 720p
8- Powerful GPU SGX 540 Vs 531