Never tried a 3rd party on my end. Canon lenses kasi are not that expensive compared to nikon's. Anyways, each has its own edge naman, that's why online reviews are there to back you up before buying an equipment. its better din siguro if you have friend na merong third party lenses so you can have a feel of what it is maybe even better if your friend has the lens you're eyeing for. Just pray for a good copy nalang kasi kahit naman nikon or canon lenses minsan sumasablay rin talaga so you can never be so sure. but all in all it all depends on the composition and eye. sabi nga nung friend ko "your lens is a tool, no matter how expensive it is, if you don't know how to use it right, it's worth nothing."