The Pi TV HAT is great but,
To be truly great HAT it would great to have Dual Tuner or even better Quad Tuner build in.
Why Dual/Quad Tuner?
To be able to Record/Watch/Stream from more than one MUX at the same time
Here in the UK there is 9 MUXes in London (3 of them T2).
Why Multi standard?
Digital TV is not about DVB-T/T2.
How about DVB-S2X satellite tuner and DVB-C/C2 for Cable TV
Or the ATSC for the USA, Canada, Mexico and South Korea
ISDB-T for Brazil, Latin America and Japan
and last the DTMB for China, Cuba, Hong-Kong and Pakistan