I purchased this product specifically because I'd recently bought Photoshop CS4, and wanted to use a pen with it. I looked at Wacom tablets but the high price put me off. The Trust Slimline range caught my attention. I bought it and installed it (some initial problems were my own fault - it is REALLY IMPORTANT to remove any previous tablet drivers before installing a new one!!! Otherwise the pen just won't track properly) and was quite impressed. The nib can be set to be so sensitive that the slightest touch acts as a "left click" - this avoids the inaccuracies that can creep in if you have to actively 'tap' the nib to click. Tracking was pixel perfect, and using the pen to control Windows apps and programs like Paintshop Pro was a doddle: very intuitive. On the whole, I thoroughly recommend this tablet.
HOWEVER - I did get a shock and a disappointment when i came to try and use it to draw in Photoshop CS4. It doesn't. Period. You can use it to control menus and options, but it won't act as a drawing pen in CS4. I did some probing on the net and found that many CS4 users have the same complaint: it appears CS4 only supports Wacom tablets. Adobe's own help team admitted that this seemed to be the case. No fixes. This apparently applies to Photoshop CS2 and onwards.
So: a very good pen, but don't buy it if you're intending to use it with CS2, 3, or 4.