Hedge trimmers that collect the trimmings - advice please

[Obelixx]

Not so sure where to post this so hope here is OK.

I am thinking of getting one of those new hedge trimmmers with a covered blade that sucks up all the cuttings and collects them for you.  Has anyone bought one and if so, does it work well?  I have about 20metres of 2m high inherited conifer hedge to renovate and smarten up plus 20 m of hawthorn hedge and 35 metres of holly hedge and lots of baby box hedge which will soon be in need of trimming and a dwarf conifer hedge round another bed so, on the face of it, such a machine should be good but not if it clogs easily or doesn't suck up all the mess.

[Obelixx]

[dtw]

I haven't seen one, but I should imagine that it would get a bit heavy after only a short while.
Would it suck up the long bits as well as the very short bits?

Do you have a link or picture?

[Obelixx]

They've been advertised alot in gardeing magazines and have the usual blade but covered with a round head and with a trailing tube that funnels the cuttings to a collection point.  There are two sizes and weights.  Here's a similar model so you get the idea - http://www.tradekey.com/selloffer_view/id/203559.htm