Even the cheapest injectors will get the job done - a lot has to do with technique (what in life doesn't?).
When you inject don't try to push all the fluid into one spot (now that sounds downright rude!) - inject some, pull back a bit and angle the needle to a new spot, inject some more and repeat until the injector is empty. You actually should think of making an * shaped injection field.
Also, try and inject with the grain of the meat.
Southern Brethren BBQ Competition Team
"It's all about getting paid!" - Myron Mixon
"I love being hated in my hometown!" - David Hair
KingFisher Gator Rotisserie cooker, WSM, Stainless 5 burner with IR gas grill, Turkey Fryer, Weber JD Commemorative grill, slightly used Bandera chamber for future use as a cold smoker, Masterbuilt 40" insulated ELECTRIC smoker