N4i TP's are 3, 7, 9, 11, 17, 21, 23, 25
N1 TP's use the remainder
Reception of TP's is variable based on location - local experience is best guide. Ironically, the odd shape of the old DirecTV satellite [N4i] reception footprint is a bonus in the Caribbean - we get better signals on that than via N1
CBC NewsWorld moved from TP 24 on N1 to TP 21 on N4i
The suffering is spread around - As an example of the crap shoot - we got NewsWorld back, but lost some west coast network feeds (which makes time-shift recording easier) - sigh.
Hope this helps...