A little late to the party here, but after 250 or so loops over the last 180 days on two "great golf courses," I'd like to think I have a bit of insight into the question at hand.
I'm taking the leap of faith that what was meant by the question was "does a good caddy diminish your experience in playing a great golf course for the first time." If I read it any other way the only response I can come up with is "no." The "first time" portion of the question seems to be lurking below the surface of nearly every response in this thread.
So we're discussing a purely subjective concept, in that not every "your experience" is going to be the same.
At the risk of generalizing, I'm going to lay out a few types of golfers that are going to be experiencing our hypothetical championship/great golf course for the first time along with their Caddy Enhancement Level ("CHL" on a scale of 1 to 10, 1 being the caddy might as well not be there, 10 being they'd go missing on the course if the caddy wasn't there):
1. The Charity Outing Foursome - Generally comprised of one decent player and three hacks, this group shotgun starts on the 16th hole and spends the rest of the day asking what hole they are actually on. After hitting the beer coolers for the umpteenth time, they proceed to not recognize the 16th hole when reached for the 2nd time and have to be told its time to go in. Without a caddy, the foursome would lose every golf ball received in their gratuity bag, and several extras found by their caddy as replacements (luckily, on these days there tends to be a plethora of golf ball to be found on the course). If you can talk this group into playing a scramble, you just might get around in under 5 and half hours. Often times the group's sole goal is to win low net, and they could care less about the history of the course, figuring it out for themselves or any conversation resembling a discussion of GCA. Other times they are there to drink, golf and have a good time (in varying orders of importance). Its the latter group that is going to include the caddy as one of their own and will have them sharing in the jokes and the shit-talking. In either case, the caddy is going to be a key component of their "success."
CHL: 10
2. The Gift Certificate Group - Often purchased in a silent auction or set up by a loving son for his aging Dad, this group is mainly comprised of what is often described here as the great unwashed. Truth be told, these are generally solid guys who are going to have a tremendous amount of appreciation for the opportunity. Some of them may want to figure it out for themselves, some may want to have their hands held. Almost always they want to learn about the course and the club, especially if it hosted a major. All of them are going to be shaking in their Footjoys on the first tee, and no matter how Bob Marley the caddy is, the first drive is going to be interesting.
CHL: 8
3. The Brother-in-Law - Or it could be your neighbor, work colleague or old college friend in town for the reunion. At some point you're going to have to ask each of them over for a round. This group can be a mixed bag. You can have the gracious guest who doesn't want to show up his host, or the guy who wants to settle the grudge on the course. One things for certain, there's going to be a lull in the conversation. This is usually when the guest turns to the caddy and asks "so how long have you been down here?" And when the guest realizes the caddy is actually not brain dead, the general vibe of the round picks up, the conversation starts to flow a little better between all of the parties and the golf generally improves.
CHL: 6 (can reach up to 9, but rarely slips below 6)
4. The Out of Towners - 16 guys from the same home club take 5 days to experience the best that city X has to offer, their pro makes a couple calls, they hire a bus, make some reservations for steak dinners and the first question asked of the concierge is what's the best ballet in town. There's going to be gambling, drinking and after day 2 a ton of Advil. If you're lucky, your course gets played early in the trip, and becomes the stand out because its where they all played well. If you're scheduled for day 5, forget about it. All the caddy is going to hear is how their home club beats everything in town, except for maybe that other course from two days ago the name of which the guy can't remember just now (almost always a new course with a brand name architect). Whether early or late, the caddy will provide a modicum of enhancement, whether its assisting in a clear-headed assault of the course, or guiding a muddled mind and a tired body through an 18 hole death march.
CHL: 5
5. The Rater - Sneaks out before the first official tee time of the day because they only like to play fast. Clear instructions of interation are delivered to the mandatory caddy on the first tee. States that they don't really care about their score, but won't act that way on the course. If they're playing alone, they may seek to strike up a conversation with their caddy. If playing with another rater, they're bound to spend more time nitpicking perceived flaws than focusing on the strengths of the course, and all caddies will remain an after thought only to be consulted when truly befuddled by the break on a green.
CHL: 1-3
So what's the point? No two golfers are alike, and each plays the game for different reasons, at different times, in different conditions and with different expectations. Whenever this type of question comes up around here, I always think back to my first trip to Bandon. In our group of 8, there were two guys who carried their own bags and wouldn't have taken an ounce of advice if offered. On the other end of the spectrum were two guys whose routine was take club from caddy, listen to where to hit it, swing, go back to happy place. The rest of us were somewhere in the middle. And you know what, we all had a great time. Part of that was due to the company, part from the golf, and for some of us, part of it was having good caddies out there to help us enjoy the course a bit more.