Zafira replacement stylus - good or no?

I've been looking at replacement stylus' for cartridges where the stylus is no longer commonly available - like my Ortofon DN 245. A French company called Zafira makes a replacement stylus for this, as well as older model Shures like the V-15's. Naturally these are less expensive than NOS... but my query is - are these OK? Just wondering if any members have any experience with Zafira's. A google search turns up very little - primarily vendors.