The fastest refunds for us too.
We E-filed on Jan 31st, received the state refund on Feb 3rd, Fed cash refund on the 4th and 5K in paper I-bonds on the 14th.
The I-bonds came in the following denominations - 6($50), 1($200), 1($500) and 4($1,000) each mailed separately, so 12 envelopes!