Thinking of buying this one [[www.currys.co.uk/gbuk/logik-l65scss11-slow-cooker-stainless-steel-08616498-pdt.html?intcmpid=display~RR~Household%20Appliances~08616498 link]]. It seems a good price but I have no idea what I should be looking for. What features/power/ capacity etc should I go for?