I don't own a crockpot...
When I bought my Crock Pot I emailed the company with exactly that question. The customer service rep relied that at both settings the top temp was 215 but that in the case of low heat, it took longer to reach that temp (a smaller coil I would surmise). By chance, this past weekend on one of Chris Kimball's shows on PBS, either America's Test Kitchen or Cook's Country, they did a new rating of slow cookers and top rated those that achieved something like a top temp of 210 and held it steadily. I think the top rated one may have a digital Crock Pot but someone with a subscription to their site could provide that info.
I guess the advantage of the crockpot (Ipaid less than $20 for my 5 qt at Macy's and it came with a mini one for dips) is that you don't need to keep the oven heated for all those hours.