I'm in Borovets now - skiing is possible and the lift queues are not too bad - only to come back from the top at the end of the day because you can only ski to the middle station. Don't worry about the snow!
came back on saturday, snow not brill but possible to ski in unperfect conditions, huge queues but it really depends on the individual whether its acceptable or not,had a good time but think you either love bulgaria or hate it (think turkey with snow) If I could have afforded austria for my family of five I would have booked that but couldnt so bulgaria was fine