Is sonic electronix and onlinecarstereo.com good websites to buy car audio?

Im thinking bout getting a double din radio. At sonic electronix its $349 and at onlinecarstereo its $319|||i have not bought from them but i have bought from www.techronics.com and it was a pleasure, check them out they'll probably be cheaper than both sonic and online.|||I have bought several items from sonicelectronix. No problems at all.