My 17 month old dd sleeps a lot and still has two naps. Her times are as follows:
Up - 8.30am Morning nap - 10.30-12noon Afternoon nap - 3-5pm Bed - 8.30pm (our times are later as we live in Spain where everyone goes to bed later!)
She was sleeping through 12 full hours at a v young age and had 3 naps a day until she was 8 months old. She's always been a very well-rested child, and I've loved the peace and quiet, but like mrswill says, I'd like to get out more now!! I think she's going to drop the morning nap soon though, because it's more often only an hour, which is unusual for her. It used to be two 2 hour naps a day and 12 hours at night - a total of 16 hours! She doesn't sleep in the car or buggy either, but like I say, I've enjoyed the free time.
It's not always all roses in the pispirispis household though. Dd has 16 teeth now and we've had loads of nights when she's been waking up screaming every few hours and going nuts when you put her to bed. Her eye teeth were a complete nightmare, and she got hand foot and mouth disease as well - 10 days of terrible sleep! But when she's not ill she's an amazing sleeper.
The thing is, at the minute her sleeping is all weird - over the past two weeks we've had screaming at bedtime, screaming at 4am nearly every night, difficulty with naps... I have no idea what's going on! I've been reading a bit about the 18 month sleep regression, so maybe it's that. She has been better over this last few days, but today she had a lot of trouble getting to sleep for her afternoon nap, so maybe she is ready to go down to one... Just prior to all this malarky (at 16 months) she was just like your lo, sleeping 16 hours a day, so beware!