I already have several computers mining bitcoins using a combination of CPU/GPU/USB ASIC Block Erupters. Recently, I've been noticing that the GPU/CPU Mining, especially the CPU miners, have been having very little effect on my overall mining progress. All the CPU/GPU's combined, I probably have around 200 MH/s worth of mining power while the ASIC devices account for about 2 GH/s.

Should I stop mining bitcoins with the CPU/GPU and use them for mining Litecoins instead while leaving the ASIC devices to mine bitcoins? Would that be the best use of my available computing resources?