these 2 devices have been great.
when i go out to repair a pin they come with me in my brief case style tool box.
i have never had to change a handle or element and to get 11 years out of a soldering iron is pretty good in my books.
i haven't even changed the sleeve which holds the tips on.
i dont know if this model is still available but if it is and its a genuine hakko and if you are after an iron that will be around for years then buy one of these.
i rate the 936 a 10 out of 10.

as far as the denon SC7000Z goes its got great suction. the only down fall is if you dont let it heat up properly ( 5 mins ) then you may have a problem with the solder going cold at the tool end of the tip and blocking the hole. if this happens just turn up the heat for a while and use the wire probes that are supplied with it to unblock it.
it has two fillters, one in the back of the collection chamber and one in the main unit which is easy to change with out pulling it apart.
the second filter which is quite small is the same as a cigarette filter and avilable for about $1 for 50.
the main filter is supplied with the collection chamber, i cant remember what the last one cost me as it was a couple of years ago.
the SC7000Z has an adjustable tempreture.
i would give the denon about a 9 out of 10 due to the problem with the solder blockage.