Absolutely, unless you are a very experienced dinghy sailor; and you will probably still at least put the boat on it's side at some time along the way! The only reason I did not affix one to my mast is that my 14.2 is a keel model (200 lb 2foot keel) and does not need the buoyancy. Otherwise it is one of the best investments you can make in a fantastic, but tender, sailing dinghy. The peace of mind will be worth the hassle alone, and if you will have any crew you owe it to them as well. Safety first, fun next! Only problem I see is how to attach a masthead fly, which sailing larger boats addicted me to.
I'm in the same boat .... (sorry, I'm a dad and required by law to pause here and make sure that all uninterested parties fully see any double meanings or puns my small brain might come up with) (do you get it? like really get it?) ... I have a Baby Bob in a box as of a few months ago and would fully agree with Kerrcat above that one primary motivation is the peace of mind associated with having it. As a newbie sailor who dwells on every online forum comment that mentions imminent turtling doom on my Capri, I found myself really stressed out on the water much of the time last year because in the back of my mind the whole boat was always 3 seconds away from turtling. That being said: the Baby Bob is still in a box and now I have another project looming to build something to attach it, i.e. not sail for a while. Given that it's mid-summer I may just swallow my pride and go with the empty Tide detergent jugs hoisted up the mast... but I am looking forward to being on the water with my mind free of (at least) the possibility of turtling.
Here is another thought, now that I have come in from work, too hot ( 94) and humid here and no wind. So, thought I would crank the computer back up. Tomorrow looks like mid 80's and a northeast wind in southside Virginia. Anything up to about 10 knots is great on the lake, above that takes more concentration, and gusts to 15 or more make it interesting. But, I have reef points in my mainsail, a single line reefing system, and roller furled jib, and am not too proud to reef the main and enjoy more wind. If you don't have reefing capability then I put that right up there with having a baby bob installed, especially with the center boarded 14.2. Just another thought. There are quite a few threads on this site regarding these points, North Sails has a great post specifically regarding setting the sails on a 14.2, and the UCLA sailing center manual, older version, is based on the 14.2's which they use at the sailing school (also mentioned recently in a post).
A few of my posts show how I mount my Baby Bob. A custom bracket makes it simple to use. Sporty days I put it on. Never have dumped her yet. Got the bottom rail submerged enough to get water in the cockpit once but if you let the boat go where it wants and shift your weight properly she will round up and carry on. One of my Capri buddies dumped his and turtled the mast into the mud bottom. No fun there!
See how the Bob doesn't look too big. And the other pic shows the reefed main tied off on the boom. Makes a huge difference in how the gusts slam the boat. Even on windy days, with reefed main and the Bob I have no fear!
Now I bet the fixed keel Capri is a much stiffer boat than swing, I would love to try one out one day.
My Mod3 14.2K has a Selden mast, which is sealed, and has a composite head fitting for an external main halyard; no jib halyard since the boat was fitted with a roller furler. I fabricated a support for my larger Windex indicator and attached it to the port side of the mast just below the head fitting using a tap and drill method with stainless machine screws, bedded with 5200 sealant. I think that you could fabricate a support for a bob using flat aluminum stock, two "legs" with one on either side of the mast and extending above the head fitting, a cross support(s) for stability, attach them the same way I did for the Windex and bed for water tightness. Two screws on either side should provide enough support if properly spaced and bedded. I don't think that I would want to mount any type of bracket to the composite head fitting. Hopefully you will get some additional input from a Mod3 bob user.
Because of the keel on my 14.2K I have not felt the need to have a bob and preferred to have a large Windex at the top of the mast.