While I started with the .32 spl., which I still have, I have used the .30-30 off and on for 40 years. It is a fun gun. In the timber of the east for deer or bear, it is ok. I have used it in the west on deer, antelope, coyotes, and mt. lion, and varmits like rabbits, chucks and p. dogs. It is a fun gun that can preform very well at modest ranges. I really prefer it to the .243 for medium game up to say 150 yards. With the new ammo it will stretch even a bit farther.
When I hunt does, or just want a deer, it is fine. If I don't get one today, there will be another day. However, I am not so foolish to think I would trek into country where I might get a chance at a mulie trophy of a life carrying one of my .30-30's.
While the .30 has taken all kinds of game, it must be remembered this was often done by folks who lived there, and either it was the only weapon at hand, or they had lots of time to hunt so if it didn't happen today it would tommorow.
Another thing we must keep in mind when talking about this old round is for years it was the cheapest rifle on the market except military stuff. When I was a kid, they could be bought from $35-50 bucks used. Model 70's went for twice that. So lots were sold to casual hunters who often took out standing game because it was the only gun they had.
When I look back at the tales of hunters from early in the 1900's, often the guy who was a serious hunter had a model 95 in one of the popular cabibers, or a remodeled Springfield. They wanted the most effective round to make their hunt successful just as hunters do today.
Not everyone can use or has use for a magnum rifle or even a .30-06, but I for those who can and do have use for them and are able to use them effectively, they are great rounds.
At the same time if you are only shooting deer at 50 yards in the timber, a 30-30 is fine. As Sourdough found with new ammo the range is extended, if I were shooting caribou for meat, it could work. All of the caribou I shot could have been taken with the .30-30, but if I were leaving for a caribou hunt tomorrow, which would involve a great deal of expense and travel, the .30-30 would be in the gun safe.