Some quite interesting comments.
No mention of the impact omn the PNF of "flying all the way to cruise level"
No mention of RVSM either.
Where is this happening because if someone finds a nice quiet place and hand flies to 10,000 then that is nice but as someone else said once established in a long climb in a straight line what is the problem (unless you can't trim) - those with autotrim not included!!
For arrival in my experience there are the busy TMA's where maximum crew capacity is best and the very quiet places - with almost zero atc where again maximum crew capacity is best.
So yes great idea to hand-fly the ils when established but one has to ask - in the situations where you can handfly without overloading the pnf/pm, and it is not in a straight line to a much higher level then fill your boots (for those few seconds)
Want to keep current with handflying then find a piper cub and a windy day!!