Nothing can beat hacking on a horse that enjoys it in some of the finest, most peaceful countryside on offer. I can imagine it'd be stressful if your horse didn't enjoy it, but on one that really likes getting out and about and isn't going to spook at everything thats slightly different from last time, it's the best thing ever!
My first share pony taught me the joy of hacking. We didn't go for long hacks at all, but as soon as he stepped out of the yard he would really walk out and he was a completely different pony to the dead and unresponsive fellow you got if you tried to school. His ears would prick up and he'd really march forwards and he just made me see how exciting and enjoyable hacking can be. He completely loved hacking, more than even his food perhaps, and he really passed that mindset on to me too. Thank you Lucky!