Vista - preformance stats

Does anybody want to have a go at trying to work out the meaning of
the following preformance stats

I had expected the first set, to be faster than the second set, given
that the second set bascailly has to make a new array each time in the
pipeline when casting the enumerator, since internally powershell is
sure to be using a list..
however it seems the overhead of processing the PROCESS { } area in a
scriptblock takes more effort than even CLONE()ing arrays

$top = 30000
"BASE"
(measure-Command { $a = 1..$top | % { $_ } }).totalseconds
"PROCESS"
(measure-Command { $a = 1..$top | & { process { $_ }} | %
{ $_ } }).totalseconds
(measure-Command { $a = 1..$top | & { process { $_ }} | & { process
{ $_ }} |% { $_ } }).totalseconds
(measure-Command { $a = 1..$top | & { process { $_ }} | & { process
{ $_ }} | & { process { $_ }} | % { $_ } }).totalseconds
'$INPUT'
(measure-Command { $a = 1..$top | & { [object[]]$input } | %
{ $_ } }).totalseconds
(measure-Command { $a = 1..$top | & { [object[]]$input }| &
{ [object[]]$input }|% { $_ } }).totalseconds
(measure-Command { $a = 1..$top | & { [object[]]$input } | &
{ [object[]]$input } | & { [object[]]$input } | %
{ $_ } }).totalseconds
(measure-Command { $a = 1..$top | & { $input.Clone() } | &
{ $input.Clone() } | & { $input.Clone() } | % { $_ } }).totalseconds