These have been round for a while now and takes some beating as a nano circulation pump for the price.

Good points.
1/ Quite small.
2/ Good spread from water outlet.
3/ Efficent just 4.5watts.
4/ Magnetic mount makes it nice and secure so no suckers to go hard.
5/ Easy to maintain.
6/ VGVFM at around £21 each at some LFS's at the time of writing.
7/ Quiet.

Down sides.
1/ Can't be used with a pulse timer or it will reduce it's life.
2/ Limited pump head movement direction when fixed in tank.