The Mach Xtreme MX-DS Turbo SSD is one of the fastest Sandforce 6 Gbps drives we have seen so far. It offers outstanding performance, even when compared to competing drives with higher capacities. The same SSD using the same controller, firmware & flash chips will be faster, the larger its capacity is. For example the OCZ Vertex 3 240 GB is about 1% faster than the MX-DS Turbo, but we are comparing 240 GB and 120 GB drives here. If both drives were of the same capacity we'd see MX DS Turbo end up a few % faster than the OCZ Vertex 3.
Since this SSD is sitting at the upper end of the performance spectrum, Mach Xtreme is asking a price premium for it. With 180 € it is certainly not cheap. For example, you can get the OCZ Agility 3 for 135 €, which is 25% cheaper, but only a few % slower in performance. Another price/performance option is the Crucial M4 Series which has recently seen a firmware upgrade for improved performance. Overall I'd say the pricing of the MX DS Turbo is a bit too high to make a big splash on the market.
As always, any SSD will bring massive performance improvement over a traditional HDD - probably the best update you could pick. For optimum performance it is recommended to pair modern SATA 6 Gbps SSDs with the matching interface on the motherboard side, otherwise you'd see a real-life performance difference of around 10% which it not negligible but also not as big as what you would expect from double raw interface bandwidth.