I can't really imagine an articulated bus winding its way around Botanic Avenue and University Avenue and out onto the Ormeau Road. I lived at the top of the Ormeau Road for two years and every afternoon from about 3:15 to 4:30 all the 84 buses were filled to capacity and often didn't stop at one or more of the Botanic Avenue bus stops. The whole route was crying out for extra capacity and I think the double deckers have really proved their worth. On the first day in service the Schools' rugby final was on and Methody school had a half day; I met one of the double deckers on the Ormeau Bridge (I was on the other one) and the top deck was full of Methody people; the bus had been able to absorb the extra capacity and was very useful.
Aside from the articulated buses being awkward, people (including me I suppose) think they're a bit strange and would therefore be less enthusiastic about using them. For people to like the buses being used in service and feel comfortable about getting on them is very important as it will encourage increased usage. I remember it might have been in the 25 years forward with Ulsterbus booklet or something like that Ted Hesketh encouraging people to come and travel on a bus to re-live the nostalgia of travelling to school by bus and see how the buses in service now have improved.
With double deckers you can sit upstairs and have a really good view of everything and it can make the journey much more enjoyable just because of your sitting position, completely separately from a bus enthusiast's point of view. I haven't been upstairs since the first day so I don't know if there's any vandalism but the driver has quite a good view (except the front 1 or 2 seats) from the video screen in his cab.
If I remember correctly the garage in Short Strand depot is big enough to accomodate Double Deckers and there might be space in GVS as well. Are there many low bridges still on bus routes? I thought most of them had been demolished when the UTA closed the railway lines.