I try to use strict and loose form at different times. When I want to increase the weight i am lifting I loosen up for few weeks and then go back to strict and it tends to allow me to use the strict form with more weight onc ei put on some more mass in a certain area. I really dont pay attention all that much to others. You have to learn your body and what works for you. I beleive every 2-3 weeks weight amount or reps should increase. If it doesnt i take a look at what i could be doing wrong and make changes. I document everything i do on a weekly basis and try to improve week after week. I dont go by the mirror all that much.