I manage a fleet of servers with Fusion IO cards, if your suffering poor write performance then you're doing something horridly wrong. Random writes is exactly where these cards absolutely scream along. If you want to do VDI, then you need to spend the proper money on infrastructure. Assuming your $180k figure is correct, amortised out over 3 years you're looking at less than 20 dollars per user (inc interest). The biggest fault most people make is undersizing their infrastructure and somehow thinking this will lead to "savings".