I'd choose a Brora anyday.
The few Port Ellens I've tried (only three different ones in total, I'm afraid) were good and enjoyable whiskies, but - at the end of the day - they were just typical Islay malts. If you'd told me I was drinking Caol Ila or an older Bowmore, I'd have believed you.
Brora, on the other hand, is a bit more unique. It's wonderfully "Highland" in style, with beautiful coastal characteristics that, IMHO, are only found elsewhere in Clynelish (obviously), Talisker, and perhaps Highland Park. Whilst there's a hint of peat in there, the general complexity of Brora malts always amaze me.
If I was asked to describe Brora, I'd say, "Take the best elements of Speyside and stick them into a great Island malt like Highland Park."
I've had many Broras, and they've all been great.
And perhaps most importantly, as mentioned by others above, Brora doesn't quite attract the same ridiculous prices that PE bottlings do.