The problem with many Amiga accelerators is that their memory controller only supports 2k refresh, whereas most newer SIMMs use 4k refresh. In that case, only half of the memory is 'seen' by the memory controller. Some of the latest designed Amiga accelerators, like Blizzard 1260 and BlizzardPPC, support 4k refresh, but I don't know about the Cyberstorm line.
Speaking of memory, I just won an auction for two 128MB 50ns 72-pins SIMMs on eBay. I plan to use them in my BlizzardPPC, but the problem is that the DRAM chips on it are designed for 3.3V whereas standard SIMM voltage is 5V. We'll see what happens...