The Lowrance is worth the extra $$. It has a better power and also IMHO quicker detailing and reception. The internal GPS is a great feature and I have heard good things about them. The software capabilities should be the same but it may be easier to get updates on the Lowrance unit. You must consider though if the unit need repair later on with the GPS reciever that you will lose the whole unit and be without a sonar as well. Either way you will be happy with your choices.