Porting seems to be a love it or hate it type thing.
There's many types/styles of porting and from what I've seen, the bigger the caliber the more notible the feel when the gun is ported correctly.
For example, if you've ever shot guns like 30-06 or 300 Win Mags you may have woke up the next day with a bruised shoulder. If you shot a ported or comped gun like a Browning rifle with those same calibers, but that rifle had the BOSS system in place and adjusted properly, your shoulder would not be bruised the next day.
Compensating or porting can be a problem for night shooting because of the muzzle blast coming out of the side or top of the gun. It can hurt your eyes if they (your eyes) have adjusted for the darkness.
As pointed out above, the felt muzzly blast will be noticably louder due to the same reason. The blast is no longer just going down range, but is now being disbursed out the side or top of the barrel so in effect it is louder near you.
Then there's the cleaning of a ported barrel. That becomes a little more in volved and if you shoot a lot of lead bullets, that can now close up the porting and need to be cleaned out as some of the lead will deposit in the port holes.
You should probably try shooting someones ported gun before you send your gun in.
Again, some people love porting and others hate it.
Good luck, Jeff (GUNKWAZY)