I am a travel agent so I would recommend one! We know the ins and outs of these ships and where the better cabins are. Also if there is a price reduction or a sale we are always notified and can get an adjustment or onboard credit for you!
I have never used a travel agent in my life but then its all a matter of what you prefer but if I had 3 couples going with me, I would probably be inclined to use one. I am a solo traveler and do everything and all the research myself and love it!
I would recommend a travel agent as well. It costs you nothing and your are getting their expertise and they will have your best interest in mind, not the cruise lines. If you book direct, most of the agents who help with your reservation are in Wichita and have never set foot on a cruise ship.
While there may be some good travel agents left, but most/many have no experience except what they see in the brochures. But, as someone said above your comfort level of booking your own trips and asking the right questions etc. is up to you. Our friend is a good, TA and some times I book with her if her agency gives some OBC or has some trips, perks, I cannot get anywhere else. Most of the time I do my own thing, rather than having to make changes through a TA(PITA), RC's trip planners can be very helpful and do somethings for you that a TA cannot do or easily do, they see basically the same screen as you do on your computer. I just had this happen, it was not a upgrade or anything like that, but could not do it on RC's web site and it took her a while to do it, asking permission I guess.
That is why it's advisable to use a CLIA (Cruise Lines International Association) Certified Travel Agent who must pass tests, amass ship inspections and sail on a certain number of cruises of varying lengths to be certified.
I only use TAs if the agency is giving additional perks, I simply prefer to do my own bookings I feel more comfortable with doing my own thing, if you are not willing or capable of organizing your own trips use a TA. Good TAs, take no offense, but most TAs I have dealt with are so incompetent, heck, I have seen some that did not know where Alaska or anything about Alaska,and were and were selling cruises/tours there. Mostly problems originating from TAs are not big one, but pain in the *** ones. Most TAs do a great job of booking already arranged tours/cruises, but extra days before/after that, watch out and double check your itinerary.
I'm fortunate, I do have a good TA who is also a friend.