The pros and cons of going racing as part of making a living from betting.
Not clear cut, as I knew someone who, upon the advent of exchanges, stopped going then started again.
At home, he saved all the expenses and could get even better odds than were ever available, fleetingly, in isolated back-line places at the track.
But he lost out on paddock inspection and things like, as alluded go on another thread, visibility on the conspicuous presence - or equally-conspicuous absence - of the more notorious connections when their horses were running.
And of course you can still use the machine on your phone at the track, though at many minor meetings in particular, liquidity isn't what it was.