My karate practice is manifested in naihanchi, passai, kusanku, gojushiho, chinto, tensho, sanchin and seinchin.
We do practice sparing at all different levels. We also do numerous other drills designed to build a variety of skill sets.
IMHO sparring is useful at any level. I have trained in no- contact sparring all the way to full- contact kyokushin style and have benefitted from every level of sparing. I agree with Victor Sensei that the best skills do come from superior drills and not from "sparrring". Sparring is useful and fun but it does reinforce a "dual" mentality. If you study bunkai of traditional kata, many of them include strategy for fighting numerous opponents in numerous scenarios. They do work in the sparring ring as well (no matter what McArthy sensei says). At least the shorin bunkai that I have seen includes practical and natural footwork utilized against multiple opponents.
Kyokushin style sparring has limitations as well. You can't punch or elbow to the head, minimal grappling and no direct kicks against joints. All of these may crop up in a "real" encounter.
Also, using a bogu or other protection is a reality when insurance is involved. Its true it doesn't have the same feel if you take a shot to the gut, but even kyokushin, Ashihara, Enshin etc. stylists cannot take a knife to the gut. I don't care how good your sanchin is. So you need tai sabaki skills as well.
At the end of it all, you have to enjoy your training. As I continue in my 19th year of karate training, I find that kata practiced medium speed in a flow manner and kahkie drills work amazingly well. And, it works for me in sparring matches as well.
Enjoy your training!!