Here's what I've found out from my research
Cozy: I've been using them for a few months, but I have one tenants that frequently has non sufficient funds. The problem with Cozy is that I don't find out until the 4th or 5th! By the time the tenant can get around to paying me in cash/check/money order/etc. I'm deep into the month. Cash flow isn't so much the issue, but knowledge - I want to know on the 1st if my tenants have enough to pay or not. So I'm looking for a new solution.
Giving tenants bank acct and routing: According to Bank of America it's not a big deal. They can deposit into your account, but there are enough security measures to not worry about them being able to take money out.
Intuit: At 50 cents a transaction for ACH that's a pretty good deal. And according to the rep I spoke with, if the tenant doesn't have enough money in their account they can't process the payment - unlike Cozy.
Venmo: I've been doing some transactions with them recently and have not had any complaints! I'd like to be able to set up recurring payments, which is not a feature they currently have.
Other solutions like Erentpayment, etc: Most other solutions I've found so far seem to be more spendy. For example if I switch all my residents to $2-$3 per transaction, that's about $800 per year out of my pocket. Could I pass the cost on to the tenant? Sure. But if I can find a free solution that's even better.