I don't know anything about these specific bikes, but in general, you'll get what you pay for. A lot of these bargain bikes tend to have low quality and non-standard parts and are very difficult to service. Expect lots of deep sighs, frowns and big estimates when you bring it into a bike shop for repairs. Have you considered spending may €150-€200 on a decent quality 2nd hand bike? This is a good time of year to buy, as many students return home from college and want to get rid of their bikes before they go.