I'm on my 3rd car with V-Kool Elite. Have looked at Llumar on a friend's Mazda, can't really tell the difference. Go for one with good workmanship since you're going to need that when the film eventually gives trouble. I've been very happy with V-Kool and Tint Shoppe.
FWIW V-Kool, Llumar and Huper Optik are all owned by the same parent company (Solutia) for several years already
I'm on my 3rd car with V Kool too. Elite is superb in heat rejection but now on V Kool secure. Best of both world.