Pottz
i did some looking and found another from IVAC thats much cheaper and not only shows when the drum is full but also what level the bin is at. i may go with this one ?
Just goes to prove reviews serve a purpose... if only to make people go and look for alternatives... Just write a review when you get it.
Had a look at your discovery... looked interesting... loved that progress "meter" (better than imperial). 

Already having something, I saw little benefit (for me short of disappointment) in reading the entire write up, but didn't detect an in your face warning (strobe or siren) when full.  
Just wondering how in your face the "small" display will alert you if the dusty is hidden in a corner.

If your first cut is too short... Take the second cut from the longer end... LBD