Today I made my first HF voice contact for over a year (and the first voice QSO of 2014). 99% of the time the HF radio gets used to transmit and receive WSPR, with a little bit of other data modes. For that, the 5 watts from my Flex1500 is good enough (hardly anybody uses over 5 watts on WSPR), on SSB it's not that good compared to the usual 100 watts most people run.
But I had my microphone plugged in for a change (it's the one off my FT-817, the wiring is the same) and called GB5LBC (Roa Island lifeboat station) on 7.180 MHz, who was only 7.3Km away from me. That worked OK and it was the furthest this Flex1500 has ever got on SSB since I bought it.