I have flown in to TPA a fair few times but always on internal flights so have never had long to wait for immigration or customs...no time at all in fact! It's a nice enough airport to depart from, nothing special. Security wait times were pretty much the same as any other airport I've used. It does seem to offer fairly standard airport facilities. A few fast food places, some shops and free wifi.
I'll be visiting again in May, although once more I'm arriving on a domestic leg from ATL. I'm departing from MIA about 2 weeks later, judging from the immigration horror stories this is the right direction to be going in when using MIA!
Must say that my worst US Airport experience has been ORD...2 hour wait to be spoken to rudely and have my belongings strewn out over a table and scrutinized because I had the temerity to declare the confectionery I was bringing in!
