Just got mine installed this morning, just tested a short while then had to go to work!
First impressions - HD is HD, so it's much better when comparing with the SD channels. Disappointment - SD channels don't look any better on B.yond, I was hoping the HDMI connection might make things better... bummer!!
The interface is slicker and much more responsive, especially compared with my old Max interface. Changing channels, checking info and surfing is much improved now. Getting the remote to work with my Sammy was a breeze, and I haven't noticed any serious audio problems (yet).
Note of advice: the installers are in a great hurry, so grab a slot if they call you. I know 1 guy who wanted to postpone his 8.30am slot because he had to take his wife marketing (!!). He was given a new slot 3 days later!
Also, the installers only do exposed wire installation (unless you want to use the old cable - I changed mine), and will not do any removal of the old internal cabling. This is to save their time, and to avoid any hassle over damage to walls because of removing the cable. Apparently, Astro has instructed them to walk away and reschedule if any subscriber insists on them removing the old cable!