You'll get a mixed response from most people.
Personally from my point of view. A Dual-Wield, Heavy Armour Breton is a complete faceroll on Master. You do so much damage and have so much Magical Resistance even Ancient Dragons are a joke. You can stand there an entire day being flamed by one and you wouldn't even notice.
Of course any race can have a high Magic Resistance through wise perk/stone selection, but Breton get it quicker, thus making the early pasts of the game rather easy.