Thank you everyone. In the end I got the birkenstocks though I did consider waiting. I wear my birkenstocks to work, yoga, the beach the supermarket all summer so I wanted a back up pair anyway. I was chatting to the young SA in birkenstocks and I told them I had decided on the birks over the DMs. They asked which DMs and one of them told me her friend had a pair for 4 weeks and still couldn't walk to university in them. I had already said I was buying the birkenstocks but that sold me.
kellygirl - yeah I agree the DMs elevate an outfit but I can get by with smart casual at work (and even some people don't bother to get to that level at work) and in the end comfort won.
Jenni - I agree that the DMs seemed too steep. Shoes are my most expensive purchases because I don't have a lot and I wear the few I have to the ground. I did consider waiting like you said but I'm looking down a 9 week term at school and I will not get to a shop, am never home to receive anything I buy online and knew that the cost per wear of the Birks would be low
Minamu - the docs didn't feel heavy but the leather felt like it might rub on the top of my foot. The SA said they would wear in but I wasn't prepared to take the risk.
Star - the price was heavy. Even birkenstocks seem expensive compared to some shoes. My son bought some slides for $30 at a menswear shop but he doesn't wear them all day and I knew the quality of birkenstocks were good.
Suntiger - thanks. I did think about clogs or the ones with the straps but decided on the Arizona as they seemed comfortable and to be honest, it started to feel like a chore deciding.