Sassa,
We opted for a nanny as i went back to FT work when DD was 6 months old (she is now 4 and i also have a DS who is 20 months). It was really more because it suited us - i need live-in as i am at the office by 7-730 and don't get home until 6/630 and DH broadly the same hours. But even if our hours could accommodate it, we wanted our child to spend most of her day in OUR home. Have the naps when i want them to so they are not overtired when i get home (the 6 or 7 times or so i used a nursery for emergency care which was paid for by the company i worked for then, i found that my 7-8 month old had 40 minute naps instead of 2 hours) We signed her up to tumble tots, music class and playgroup so we know that 3 out of 5 days they will definitely be out and about and gives the nanny a chance to meet other carers and organise playdates etc. Also, we knew we were going to have more than 1 child so once another one came along, it would be more cost effective. (Though now we have nanny + private fees for my DD, not very cost effective anymore, but hey ho).
When i come home, our current nanny would show us artwork they have done in the day (example: dried leaves picked up from the common where they went for a walk stuck on paper with lots of glittery things around), or there will be tupperware full of cookies/flapjacks which they have baked. The kitchen is already immaculately clean, the kids have been fed and bathed, and my DH and I come home to spend an hour and a half with the kids before bedtime just either playing with them or reading to them. Typically, she has also peeled potatoes and warmed up oven so it doesn't take me too long to prepare food. She then stays for 10-15 minutes downstairs to take me through the day and then she goes upstairs, and i don't see her till the next afternoon though clearly we talk/send texts throughout the day. Sometimes she makes big batches of food on Thurs and Fri and puts in freezer so i don't have to cook too much on weekend. THe kids loove her but she never tries for one second to usurp our position - and therefore the kids don't have any problems transitioning to us at night or in the weekend.
Ooooh, i think i went on far too much there. I guess i'm trying to paint you the relative calm we have at home because we are with a terrific nanny (who would be the last person to tell you she is a great nanny - i quite like humility too) - i don't think i could have achieved this at a nursery.
But if your hours permit, and you find a nursery that has been highly recommended, i am sure that would work out too.