The question of whether not its worth it varies from plane-to-plane and from pilot-to-pilot. On some planes, the flaps don't do very much and are more for asthetic appeal. On other planes, they are very functional and can be very helpful on landings. For example, on the GSP Spitfire that I had, the flaps were not split flaps and were small, so they didn't help a lot on landing. Many people with this plane preferred not to use them at all because they often made landing more difficult. On the other hand, I think most modelers with a Yellow Spit would recommend using the flaps (depending upon the wind) to slow the plane down for landing and prevent overshooting the end of the runway. On my KMP Hurricane, they are very effective in slowing the plane down and allow a steeper approach, so I always use them on landings. On my Meister ME 109 (102"), the flaps are relatively small, but they do help slow the plane down so I use them on landing, especially in calm conditions, even though with the Meister wing the plane can be landed without them.