The structure is unimportant (tenants in common, LLC, S corp), the key is that you all understand what is expected of whom. WRITE IT DOWN. Have a partnership agreement that spells out in clear language who is responsible for what, what happens with contingencies, what happens when you get into a fight (you are all friends now but be professional, what happens if you get irritated? You want a simple agreement to fall back upon that says, for example, you get 3 appraisals and average them to determine a buy-out price if one partner wants out, or if it's a vacation home, it's all cool until 3 of you want to use it at Christmas one year, so you fall back on the agreement that says you pick straws the first year for Holiday and then rotate from there). Make sure you write down the major things so you are all on the same page. Especially: what happens in a divorce??? Show it to a lawyer, don't go cheap.
Having said that my brother in law invested with 10 partners and did very well with a well thought out, compete partnership agreement over 20 years.