Off the shelf

I'm in the market for a new computer, but I haven't got a whole lot of spare cash as most of it goes towards camera gear and travel. My last three or four PC's have all been made to order by Paradigit (Dutch independent store). They used to be cheaper and better than the big brands. This time though, it seems going with a brand PC, Acer in particular, will get me a better deal - like 100 or 200 euro cheaper. I haven't been able to find any horror stories about them. Anyone out there who can tell me otherwise? Any reason why I shouldn't go for an Acer Aspire M6310 (dual core, not the quad core advertised on the page)?