tv through internet instead of cable box

On 4/25 and 26 we had no signal on TV.  Callled, and Tech was able to send signal on 4/25, but not on 4/26, saying there was a problem with the box.   (The box was only about 6 months old,)  We did receive credit on our current bill.  They sent a Tech to our home on 4/27, and he determined it was a problem with the wiring.  So, he said it would be best to get rid of the TV box and just use our xfinity internet for TV.   He also said monthly price would be less.   So far, ok, except for one night the internet went out a few times for short times.  Other then that, a few questions.  Do we still have HD?  Does data usage apply?  Should our monthly price be the same as it was with the cable box?  It's the same for our May bill (minus the credit).

Thanks.