Maybe someone would interested, so I posted the results here:

(Benchmarking on a p4 3.4G SMP debian stable-etch, 2giga ram machine, all SCM software use packages from debian stable, checkout/branch occurs on localhost)


initial speed: hg==git(3Min) >> bzr(15Min) >> svn(71Min)

checkout/clone speed: hg == git(3Min) >> svn(11Min) >> bzr(21Min)

space effiency: hg==git(123Mb) >> bzr (230Mb) >> svn(repo:82Mb+workingdir:573Mb = 655Mb)

== report ==

/usr/bin/time -o ../hginit.usage hg init
/usr/bin/time -o ../hgadd.usage hg add .
/usr/bin/time -o ../hgcommit.usage hg commit -m "first import"

real 3m25.284s
user 0m34.130s
sys 0m4.868s

/usr/bin/time -o ../gitinit.usage git init-db
/usr/bin/time -o ../gitadd.usage git add .
/usr/bin/time -o ../gitcommit.usage git commit -m "first import"

real 3m20.346s
user 0m23.061s
sys 0m5.032s

/usr/bin/time -o ../bzrinit.usage bzr init
/usr/bin/time -o ../bzradd.usage bzr add .
/usr/bin/time -o ../bzrcommit.usage bzr commit -m "first import"

real 15m10.689s
user 1m59.299s
sys 0m9.617s

svnadmin create --fs-type fsfs /home/tim/test/testsvnrepo/
svn import -m "New import" linux-2.6-2.6.18.dfsg.1 file:///home/tim/test/testsvnrepo/

real 71m3.704s
user 0m53.467s
sys 0m24.998s

#### Checkout/Branch(Clone) time ####

#time bzr clone linux-2.6-2.6.18.dfsg.1/ testbzrclone
Branched 1 revision(s).

real 21m5.351s
user 1m38.898s
sys 0m11.465s

# time hg clone linux-2.6-2.6.18.dfsg.1/ testhgclone
20690 files updated, 0 files merged, 0 files removed, 0 files unresolved

real 3m15.951s
user 0m12.449s
sys 0m4.016s

#time git-clone linux-2.6-2.6.18.dfsg.1 testgitclone
remote: Generating pack...
remote: Done counting 21351 objects.
remote: Deltifying 21351 objects.
remote: 100% (21351/21351) done
Indexing 21351 objects.
remote: Total 21351, written 21351 (delta 2213), reused 0 (delta 0)
100% (21351/21351) done
Resolving 2213 deltas.
100% (2213/2213) done
Checking files out...
100% (20323/20323) done

real 3m27.516s
user 0m59.908s
sys 0m5.132s

#time svn co file:///home/tim/test/testsvnrepo/ testsvnco
Checked out revision 1.

real 11m44.980s
user 0m35.294s
sys 0m15.849s

####SPACE USAGE ####

123M linux-2.6-2.6.18.dfsg.1/.hg
123M linux-2.6-2.6.18.dfsg.1/.git
230M linux-2.6-2.6.18.dfsg.1/.bzr
82M testsvnrepo
573M testsvnco

Note: I've installed bzr 0.18, and results shows no big difference.