Jay, I'll tell you the truth... not too much different. For the price I REALLY like the Sylvania Silverstars you can buy in the US. Good company, good price, great light. I can't see much difference out of the Osram version, and I had one bulb of each in at one time. I now have the Sylvania version in my wife's Rodeo. I probably wouldn't buy the Osram's again unless I couldn't find the Sylvania's for less than, say, $25 or so.

I have 18w Malibu bulbs from Home Depot in my driving (round) lights and they are fine. I have tried testing different bulbs in there and the 18 watters have always been brighter. I tried some 6-LED bulbs and they were DIM compared to the 18w bulb.

I've been running the 18w bulb for years and no melting or discoloration.

That being said, you DO need to test for a period of time to make sure a higher wattage bulb will be ok no matter WHERE you put it. I tried putting a higher wattage bulb in the horn lights and within a minute or so it started melting the bulb socket. I have the 6-LED bulbs in there now and they are bright and very cool (temp wise).