It's rare to find Intel's much-praised controller on mainstream SSDs, let alone one that's definitely at the bargain end of the spectrum like this Kingston 40GB. The obvious sacrifice here, since it maintains the 32MB of cache found on the Intel X25-M, is capacity - which has a dramatic negative effect on write performance.
In a nutshell, the 40GB DUK offers some of the best read performance of any SSD, far exceeding its quoted 170MB to reach a 226MB average! Kudos to Kingston for being so incredibly conservative with its figures - a virtue rarely encountered in the technology world. Then again, the quoted write performance of 40MB/s actually appears to be not only on target, in some scenarios it's optimistic as in our testing this dipped as low as 20MB/s under HDTune. Luckily for Kingston, reading is the more common action in day to day computing.
On the value front, meanwhile, we would have to say this V-Series 40GB SSD is a decent deal, at either £74 for the standard edition or £86 for the Desktop Upgrade Kit edition reviewed here. Generally its write performance will be far superior to the £100 64GB Kingston drive from the same range, which is a completely different proposition thanks to its JMicron controller. Also, JMicron controllers are incompatible with TRIM, so for Windows 7 users the choice is clear.
However, thanks to the abominable write performance and relatively tiny capacity, if you can afford to you might want to consider an alternative such as the 64GB version of the OCZ Agility, though at more than twice the price (around £160) it's a significant difference.
On a last note, while Kingston's three-year warranty is pretty much the standard period for SSDs and doesn't hold a candle to the 10-year one protecting Patriot's TorqX, you do get 24/7 technical support, which might be an important factor for the less tech savvy.
Kingston's SSDNow V Series 40GB Desktop Upgrade Kit is a bit like a Mini with a sports car's engine under its bonnet. It performs like a champion in some areas and terribly in others, but its low capacity is matched by a relatively cheap price making it an appealing proposition despite its flaws.