Big plus was the option to pay with PayPal interest free installments. However, the ordering process was not that smooth as after logging to PayPal, approving the purchase and returning to expert.de website, the process would hang. I had to repeat this several times in order to get through.
Another minus is that they offer only one shipping carrier (DPD) which limits the options to the customers as it's not as reliable as DHL and lacks the DHL Packstation option which for me is the best thing ever...
Other than that, prompt shipping and smooth overall experience.