i have some chauvet intimidator 2's (250w halogen), and some design spot 250's (msd250/2), and the intimidators often look brighter than the ds250's. i've used them together for five years. the intimidators do have a tighter beam than the ds250's which might help them a little, but the key is to only use 50 hour lamps. those elc halogen lamps are very bright when they're new, but after 50 or 60 hours, they dim to what seems like less than 20 percent of their original output.
i bought a round of 500 hour lamps once, and when one went out and i changed it, the other ones weren't even on compared to the new one. i only buy ushio elc lamps, and i replace them after every 8 shows, about 40-45 hours average, so they never go out during a show. they mix very well with the design spots. the difference in color temp is noticeable in white, but not vomit inducing, but the difference in other colors is hardly noticeable at all.