Should I keep on lifting heavy? 10 POINTS!!!!!!!!!!!!!!!!!!!!!!!!…

I am 20 years old 5"11 and 145 lb. I always lift heavy and never lower the weight I bench 270lb, bicep curl 55lb dumbbell and leg press 550lb. Some people at the gym remind me about form and how I should lower the weight. Should I take this approach and focus on form rather than always lifting heavy weights. Also I am beginning to wonder because even though I lift heavy weights my body frame stays the same and I think it is because of my form. Should I lower the weight and when I get to 10 reps increase because what I do now is as soon as I get to 5-6 reps I up the weight. Is form better to build muscle rather than heavy weight. Any advice would be appreciated.