Cree is a good brand name, but the parts are "binned", in that the production runs are tested and sorted as to their brightness vs. current drawn, and colour. Big difference in lumens between a top binned and a low binned Cree. So the fact that it's a Cree isn't a bad thing, but not a guarantee you've got a good LED, as it could be a low binned (low performing) Cree. Common in the aquarium DIY LED trade is to sell someone unknowing a low binned Cree at a high binned price.
What this means is that a replacement bulb made with low-cost low-binned LEDs may use more watts and yet have less light output than one made with a high binned LED that is using fewer watts. No way that I know of to know what you're getting other than trial and error. Which is why I'm hoping someone has found one that they can attest that it is brighter than the stock bulbs.