cassette change, will I notice difference?

After realising i needed a new cassette I got hubby/ my bike mechanic to phone lbs and have one set aside. He reserved the sram pg 1030 11-36. He always has the sram pg1050 for his bikes, so after much moaning and threatening to use his pg1050 11-36 on the shelf waiting to go on his bike,  he re phoned the bike shop and changed the order. Now here's the issue,  when I picked up the cassette it was a 12-36  Again after much debating and hubby telling me I wouldn't notice (but he would) I bought it.  Will there be much noticable difference?? Or should I try and swap the cassettes in the boxes and see if he can tell the difference