Admittedly I haven't used one but the only downside, apart from being another battery powered farkle that will need charging every few days, is that apparently the BT connection to your headset is mono, not A2DP, so not much use for music if that was a consideration. However, for PMR and GPS directions it looks like a useful device, comes with a remote PTT switch in the box. You will obviously need to buy the correct lead to connect to the PMR radio of your choice, the reputable brands; Kenwood, Motorola, Icom, Yaesu and Midland are represented, these are another £18 or so on top of the SR10 unit.
Combined price is going to add up to quite a wad of cash unless you already have the headset and radio. Also might worth asking if the internal battery is changeable. When it starts to no longer hold charge in two to three years will you need to chuck the whole thing away and buy a new SR10. ISTR that one of the Bike Bluetooth headset manufacturers expect you to do just that. Maybe that's not a concern for you though.