Mammoth is great compared to the local spots, but there's nothing too crazy about it. If you'll be there in the middle of the week you shouldn't have to worry too much about crowds, which is always nice.
There isn't any snow coming through until maybe the weekend, so you're going to basically be looking at spring conditions. Don't be in too big a hurry to get out in the AM since everything will be iced up hard from the night before. Things usually start to thaw out about halfway through the morning, and it's usually a good ride until mid afternoon when it completely turns into a slurpee.
Take the opportunity the bigger mountain provides to challenge yourself, and enjoy the longer runs.