Topband: HF Antenna question

[Dan Bookwalter]

I know this is really out of this groups subject , but , you guys  know more about antennas than any other site.
So , I may head to Barbados in February just to have fun during the ARRL CW contest ....
in my limited research i have sort of landed on this antenna ...
Comet CHA250B HF/VHF...
I have read it doesn't need radials if mounted high above ground , this antenna will be on the roof 3 stories up , I can still probably run radials all in random fashion ....
is there a better option? I can't have anything really complicated to put together ,or mount , this antenna looks easy to construct...
Dan N8DCJ
p.s. anyone have any experience using an FT891 on CW ?  with the cw filter installed