If you use 800 series couplers, they will connect to the Lionel-style couplers, but the newer 700 series do not. Since I don't have wide radius track, I truck mounted mine and have experienced no problems in normal operations. Backing a long train through the diverging route of a switch can be problematic, however, as the couplers tend to go way off center sideways. Since mine aren't longer than 5-6 cars at most, I haven't experienced derailments.
Terry