1. The glue line will show quite a bit.
2. To minimize the obvious line you can rip\crosscut and roll the piece
over for a bookmatch effect on the end and side grain.
3. If the top was 3' x 6' that's about $65 worth of 4/4 Red Oak at my
local prices. I'd spend the extra $50 and go with 6/4.
4. It's likely a few hours of extra work to do the lapping by the time
your done with all the extra work it causes. That's worth $50 bucks
right there.
5. There is always the chance of severe problems if things go bad and
regardless you'll have that glue line forever.