The cheaper SSDs tend to have worse performance than expensive ones with extensive write file operations, though it may or may not be a problem depending on how often said operations are done.
Also since cheaper SSDs tend to exclude DRAM, there's the potential to wear out faster due to using flash to cache things. Though I'm sure recent DRAMless SSDs can use system RAM if special software is installed, this doesn't bring the performance levels to SSDs with DRAM.