you can take mine out for a day if you want, and find out for yourself. since i ride ss a lot, i am happy being stood when climbing, or at least, i am quite accustomed to it. older 5s had the pivot mounted in a different place IIRC, and if the pivot isn't aligned to the chainring you're using at the time, then you will experience more bob when climbing i believe. i mostly use the middle ring as a result, and climb seated if i resort to granny ( not very often these days ).
my 5 has been used for spanish, french and swiss holidays, for thrashes over dartmoor, and very occaionally on haldon. it's also been used on uplift days at a few DH tracks. cwmcarn a few times, triscombe, gawton, and that other one up near the quantocks i can't remember the name of right now!
having recently broken my ss frame, i'm single-speeding my geared HT, and going down to two mtbs, so the 5 will come out more often when i want gears. having sort of kept the five for holidays and uplift days recently i used it on the moors a couple of times and realised what a fantastic bike it is to ride, for just tossing it off on regular riding around lustleigh, and all that stuff.
top bit of kit. unlike the HT frame i broke recently, i think if i broke the 5 i'd probably buy another one.
oh - and i bought mine SH from an orange dealer. it's an '08 for reference and i paid about 1300 quid two years ago, though i did swap out quite a few bits for personal preference. it doesn't owe me anything.