I've seen a few trucks in person with the stick on covers and I'm not a huge fan of them. I don't like how they feel when you open the door. They look decent I guess and it beats paying big $$ for the actual chrome handles.
I have the putco's too. Make sure to wipe the stock handles good with alcohol first to remove any stuff on there, then heat the handle and tape a little and press and hold it on good for around 30 seconds.
I put the Putco liquid handles on my truck, but I didn't like the quality of the handles for the price. When I opened the door, the handles were just too loose feeling and just didn't "seat" well in the housing, so I put my factory handles back on and ordered the Putco chrome covers. I like them much better.