I sell both the Britax and Narva inserts at work and side by side they are almost identical.
I only ended up with the Narva inserts as they were a considerable amount cheaper to me than the Britax.
I've been running Phillips +130 globes and they are a fantastic upgrade to both the low and high beam.
I'm not too fussed about the high beam as where I can use my high bean I turn my light bar on!
Another beauty of the Narva inserts is they are impervious to cracking after being left on all day and doing a river crossing with them left on.
The pic below is crossing the Murray River at Tom Groggin and I deliberately left the headlights on to prove they wouldn't crack.