the attachment below gives some good info and reviews
also www.skiclub.co.uk - search for borovets under resorts for some more insight
finally i seem to remember seeing some info about skiing resorts (including borovets) on www.holiday-truths.co.uk
i've never been there personally but have heard that it is a good place for cheap skiing, food and drink but the skiing facilities are nowhere near as flash as other european resorts