I don't like it because of the 2 distinct ways of pronouncing it. I've always pronounced it Air-ron so if I wanted to call a DC 'Arran' I'd probably spell it Arran - to follow on nicely from Lewis, Harris and other Hebridean islands :-)
My ds is called Arran after the Isle of Arran. it does annoy me though when people pronounce it Air-on. Also if you do spell it Arran, be prepared for all different spellings. Ds has had Arron, Aaran, Arun to name but a few!!
My son is Arran, for the scottish island. My husband grew up in prestwick in Scotland and spent a lot of his childhood looking over at the beautiful island! I think its a lovely name and any of the spellings are great.