I've put in an order for a Defy 2015 Advance SL 1. It's the model with the integrated seat post (ISP). I've never had a ISP bike before. Will I regret it? Are the limitations (lack of adjustability) too large to overcome the benefits?

I"m having doubts about the ISP. I don't plan to sell the bike after i've got it - it will be my last road bike.

Has anyone owned an ISP bike and regretted it?