Yes, traveling I 10 would be faster but the drive along the coast is beautiful! Have a great trip :)
I agree, I-10 is about 20 to 30 minutes faster but the RT 90 is a real nice trip along the coast but it goes quick. Note the vacant lots which had buildings before Katrina. Make a quick stop at the Island View Hotel & Csino in Gulfport. Also check out the dead trees in the median between Gulfport & Biloxi which various marine life and birds were carved into.
I agree with others, above. Hwy 90 was once a very lovely, pastoral trip through the LA marshes, and then along the MS Gulf Coast. If not pressed for time, we would often pick it up in New Orleans, and enjoy the trip - heck, I still remember the "old" Genitlly Hwy, and much of the original Hwy 90, prior to a major realignment, in the late '50s and '60s.
There is just not THAT much left, and time will differ by probably 45 mins. While the I-10 route does not have the history, most of that has washed away.
Now, you CAN deviate South, from I-10 to Bay St. Louis/Waveland, and pick up Hwy 90 for the final drive to Biloxi. That will probably only add about 30 mins. to the trip, and does take you along the Gulf.
Once, I would have urged you to do Hwy 90, out of New Orleans, but not post-K.
Just adding another vote for picking up Hwy 90 - recommend doing so at exit 2 in MS. You can take I-110 back up to I-10 in Biloxi for a nice trip.