This was posted awhile back, but I noted that the author (an industry professional) recently updated and is worth a repeat read.
 
http://reviews.ebay.com/DYSON-VACUUM-CLEANER-OVER-RATED-OVER-PRICED-THE-MYTH_W0QQugidZ10000000001303022
 
Carmine D.

Hello Chris:
 
From the pix and now the video, it appears that the dyson DC18 Slim may be a tad top heavy and unsteady in the upright position especially with use of attachments.  I don't have any personal knowledge and observation so I don't know if that is the case.  Maybe others who do, know its stead worthiness.  
 
Carmine D.

I've had first hand using the DC18 (UK version) and I can honestly say the machine is stable in the upright position and using the tools is a dream!  The machine follows you and does not topple over at all.  Not in my experience!  
 
The hose is very low to the floor, lower than the DC15 but does not have the flexible arm at the bottom like the DC15.  There is no pulling back on the hose from the suction unlike the DC07 (UK version) yet the tools are quite powerful!  The hose and wand diameter are the same as on the DC07, DC14 ( and previous DC04 and original DC01) unlike the DC15 which has a small wand and hose diameter!  
 
You can feel the brush bar pulling the machine and grooming the carpet pile.  My Mum has just had one to replace her DC04.  To say they have the same watt motor 1200 watt (although the DC04 is the old dual cyclone technology) the DC18 pull alot more dirt out of the carpet.
 
The only thing cause the bin capacity is smaller (I believe smaller than the DC03) it fills up quicker but is quick and easy to empty!
 
I would replace my DC15 with the DC18 Slim much btter machine lighter and you can get under furniture and skirting boards etc better due to the slim design!

Thanks JD for the DC18 clarification and details.
 
At $469, rather pricey for a lightweight of 15 pounds (almost twice the weight of ORECK XL Deluxe).  Only 200 Air Watts and less than a one half gallon dirt capacity (slightly smaller than the dirt capacity of DC21 Stowaway which is rated at 220 Air Watts).  
 
Carmine D.
 

Quote from Dyson DC18 on 04/04/07 at 3:30pm:

 
No, I haven't.  Not yet.  Glad to hear that dyson is updating their TV ad repertoire.  I'll let you now when I see it.
 
BTW, the HOOVER HSN features on April 1 were successful.  Squeezed into one of the HOME SOLUTION sessions with HOOVER products was a rerun of the DC21 launch that aired several weeks ago.  I think only because the HOOVER products sold out so quickly.  Impressive line up of HOOVER stuff and good demo's with noteworthy prices.  Including the WT 2 bagged and bagless for excellent prices.    Even the lady demo'ers were gorgeous!  In fact I believe all the HOOVER demoes were done by good looking and smart ladies.  Don't know for sure.  Taped all on the DVR and haven't viewed them all.
 
My dear Wife commented that she thought it was rare to see 2 young lovely ladies demo a HOOVER GUV.  She asked if they are pitching the GUV for FATHER's DAY (as they said) or really to Moms for MOTHER's Day.  The GUV was one of their showstoppers.  Even had the HOOVER Slider for sale!  
 
Carmine D.