I think bendies are fine but need to be used in moderation.
If you compare SBS and SMRT services, SBS wins hands down and
one of the reasons is it does not have bendy related problems.
I am amazed at how well the Tampines, Bedok, Boon Lay
interchanges are managed compared to Woodlands and Yishun. The
waiting time as well as crowd at Woodlands is often crazy and
annoying.
Imagine in Boon Lay, if you replace all the DDs with
bendies, what would happen??? Now imagine Woodlands, if you replace
bendies with DDs, how good it would be for the
commuters.
I see people here commenting on bendies who live in Bukit Merah
and for them spotting one bendy is a big thing but people who live
in Woodlands / Yishun often crib about bendies, and really wish
there were more DDs on their side of the town.
I agreed on the bolded part. 
But it is still the best and easier for SMRT to just operate 2
kinds of buses, 12m single deckers and double deckers. Their way of
maintanace are not fantastic anyway, and so the lesser the range,
the easier and cheaper for them and more efficient they will
be.
