I was 30 and my husband was 25 when we first met. I had a LOT of hesitation about dating him. I was looking for someone older who was ready to settle down, and my husband seemed young even for 25. It was awkward for the first 6 months or so, but eventually he grew up a bit and I let my hair down a bit more, and it's been 7 years so far and I don't notice the age difference at all anymore.
I think that the compatibility lies not so much in physical age, but rather 'point in life'. My H and I were at dramatically different points in our lives, which contributed to our relationship struggles much more than our physical ages. But we got through it and I'm still 3000% positive that I made the right choice