We've just bought one of those at work, says it's 68db on the back but it's bloody noisy. Apart from that you can't really go wrong for 42 quid. Runs a 300w drill all day on one tank.
68db is noisy have a look at this table, it stops at 65db, for every extra 3db the noise level doubles, its an expontential thing, you might want to shroud the genny and direct the noise up. The table says that serious damge occurs at 65db, lets hope its not your campsite!!

Indirect damage
As well as this direct damage to hearing, constant unwanted noise is very stressful, even at lower levels, causing rises in blood pressure and heart rate, or disturbing sleep (even noise as low as 30 decibels can affect sleep if it is continuous).
Research has shown that:
- at 55-60 decibels (dB) noise creates annoyance
- at 60-65 dB annoyance increases considerably
- above 65 dB serious damage caused by noise arises