The best $500 unit for you is the one you choose after researching the units and you deciding what's best for you. Everyone can and will give you their biased opinions. What are opinions like? I know my response sounds like a copout but it's the truth.
Knowledge is power and you'll be the most happy with the units you picked based on what YOU read. Plus the more you research the better you'll understand what each unit can and cannot do, and IMO will save you some time when you finally get it on the water.
Good luck, give us a review when you get one!