The OFB one shows a brand new 125mm APFSDS round
Well, the ch***** there didn't even know that Arjun needs a 120mm APFSDS and kept insisting that it needed a 125mm round. And kept insisting that Vijayanta had a 120mm gun. After that I left the OFB stall. There was no other "knowledgeable" person around. I have observed over the last AI and this one, that quite a few people from PSUs manning the stalls are people filled with a sense of self-importance, while knowing very little. In stark contrast with people from DRDO stalls - with very, very few exceptions, all of them know their stuff and are very willing to share their knowledge and information.
Once you speak to a DRDO guy, you better appreciate the enormous difficulties they go through while creating products from scratch. The biggest sense I got from the stalls I visited (the vast majority were Indian stalls as I didn't care about the snooty attitude of the western goras) was that we have the potential to create the best products in most fields, only the attitude and commitment is lacking.