Probably depends on the size of the installation.
Certainly you are right about more connections and more maintenance with individual cells. When new it may not be a big issue but as they get older the connections do become an ongoing problem.
For very large installations the individual cells are probably best rather than having so many parallel strings. There is certainly the advantage that you can replace one dead cell. Unless the 6 or 12v blocks have link bars to individual cells you don't have the ability to deal with an individual sick cell and you have to try and equalise the whole block and also treat the cells that don't need it.
In the old days I think the individual large cells had a longer life but I am not convinced that progress has got us much more than cheapness and convenience now and battery management has improved drastically with modern charge controllers.
In the old days when you made batteries work for a living the heavy Plante individual cells seemed to last for many years but the original cost needed to be considered.
Today with charge controllers and nursing things with only 30% discharge there probably is far less case for the individual cells.
Most installations are now nearer float than heavy cyclic operation and modern block units seem to stand this well enough and almost certainly have far less self discharge.
In the end I suspect what you are prepared to pay for the bank will decide how long it lasts, you can't win with batteries, they die if you use them , they die if you don't and they are the thing that takes all the economics out of generating your own power.
Flux