So far, the most reported downside is that withdrawals are slow for ACH transfers, though certainly not CD maturity slow. The terms of service were recently updated to include wording that withdrawals may be slow.

4% is currently typical for savings account. If you're willing to uproot multiple banks are offering this

My credit union sits at 0.05% for savings. Their 4% rate only works for 12 months before it reverts to 1.5%

Wealthfront and Betterment are doing better than 4.5% on cash.

You can get a 3-month CD with around 5.2% APY right now. If you ladder them, you can keep a portion of your savings relatively liquid while still earning a decent, FDIC-insured yield.

For me the downside is lack of accountability and management. The only way I've found to interact with it is via the wallet app on my phone which is a PITA.

VMFXX at 5.22% makes more sense, except it's not FDIC insured.

> VMFXX

> The fund invests at least 99.5% of its total assets in cash, U.S. government securities, and/or repurchase agreements that are collateralized solely by U.S. government securities or cash (collectively, government securities).

While not explicitly FDIC insured, you can consider it backed by the full faith and credit of the US government. FDIC, Federal Reserve, it’s just splitting hairs wrt these instruments.

This is no different than an online high interest savings account. Compare the rate to banks like Ally.

4 is a pretty normal savings rate right now, 9 month CDs are at 5%+