As long as you purchase LED's that are CG certified you will be fine. I replaced the incandecent in my tri-color last year. It is actually easier to see (so I'm told) and it draws considerably less current. As with everything else in boating, don't skimp and do your homework. I think most of the questionable LED's are the bulb replacements, not the fixtures designed as LED's.
I will say that small airplanes are using LED's now. The power savings translates into weight savings, they last much longer, and they are very bright.
If you need to replace any masthead fixtures just go with LED's. The power savings is great, plus you have the added benefit of not having to change bulbs.