You should definitely check out past BP posts on Detroit if you haven't already. But in a nutshell, Detroit is a large city. By land area, it's larger than San Francisco, Boston and Manhattan put together. It had a population of almost 2 million, now it's probably 650,000 - 700,000. There are many different areas. Some are great, many are bad. Some are in between. Both the "Wow, Detroit is on a fantastic comeback" and "Detroit is a cesspool" views have enough truth to them to not be disregarded.
Anyone investing from afar should visit and spend the better part of a week in Detroit and the suburbs. Be aware that many long-distance investors have been lied to, cheated and stolen from with little recourse when investing in Detroit. Detroit doesn't need foreign investors feeding the criminal real estate cottage industry that has thrived and continues to exist here. It results in a lot of lost money and stress for the investor and more mismanaged or abandoned properties for our city.
There are compelling investments here, both in the city and in the suburbs. We need astute investors who come in with their eyes wide open and understand the risk, not just the returns. For most, investing in the suburbs is a safer bet and will be more financially successful despite the eye-popping ROI numbers put forth by some Detroit real estate promoters.
For a passionate and well-informed few, investing in the city with reputable partners may make sense, but that's maybe 5% of those who find themselves drawn to Detroit from afar. Be careful, be smart, if it sounds too good to be true it probably is.