Just an addition to point 2 Beages, I don't think that the commitment to OTC is any less than UAS, in fact the potential is there for far more.
After 6 months of basic training (MTQ1) which condenses pertty much the 1st term of RMAS into 22 weeks training you move into sub-units in the 3rd term of yr 1 for work up and special-to-arm training pre camp. You will do 1 night a week and usually 4 weekends per term while in MTQ1. In the 3rd term when you go to your sub-unit you will do at least 2 weekends learning the ropes of your sub-unit trade. You then spend 2 weeks on camp in the summer, and quite often a number of cadets stay on and do a full summer either on attachment with their sponsoring cap-badge, or in jobs in the OTC such as recruiting JOU.
When you get into year 2 and MTQ2 the term is split between sub-unit and officer training for 2 terms and this is when the commitment goes up, espcially if you are in a support arm sub-unit like RSigs or RLC. You will have a mix of MTQ2 weekends, competitions such as KG6, Courage Trophy, Ex Lightning Strike as well as weekends run by the reg army corps/regt's, your sub unit is sponsored by.This training makes up at least 2 weekends a term. The support arms usually end up doing all the other weekends as well. For each Ex a small contingent of RLC and RSigs OCdts were used for transport and comms, and this included 1st year training. This is combined with admin tasks like going in for 1/2 days during the week to move vehicles around or do post-ex admin in your sub unit. Then there is the social life, which requires organisation. The instructors have dinners every so often and rather than employ contract staff they will look for volunteers from the Ocdts to act as waiters and so on for cash (lets face it, it always comes in useful!). The RSM usually has a few MTDs in his pocket for things like the ceremonial squad too.
All in during my 1st term of my 2nd year at uni I was on ex every weekend between September and December. I did 1 training night per week and often went in on the MTQ1 training night to help my PSI and get lashed in the mess. I did most wed afternoons running vehicles around and quite a bit more besides. I earned shed loads of cash, but didn't have much time for study, so my results were not the best.
I would be a bit careful about saying that the commitment is less. Of course it will be what yu want to make it in the end, but it has a habit of drawing yu in once yu are there. The money is useful and you start to enjoy it. The other danger is theat you are not exposed to RAF ways of thinking and RAF contacts which are useful. But, you will get a far better officer training syllabus that will develp other skills such as leadership and fieldcraft than the UAS which will be beneficial for some of IOT, but it will require a lot of flexibility when you go to RAFC because they RAF think differently to the army when it comes to training officers. If you can do that, and enjoy OTC before signing up with the RAF, then it is a good option. Agree that RAF training is pants though, the "hold" system just seems to serve no other purpose than to mess Flg Off around and destroy any enthusiasm that may once have ben there. To be fair though, the army is quite capable of doing this too with it's Lts.