Floorstanders with a large sweetspot

You might want to look into waveguide designs

If you want a large sweetspot, Ohms might be a good candidate for you. They are sold direct, but do have a 4 month home trial period with a money back guarantee. (I think you're still on the hook for return shipping, but still a good deal.)

I'm not a current owner, but have had them in the past and can recommend them for any short list of candidates.

Audio Note model E is almost a floorstander and when placed in the corner will throw a huge soundstage and sweetspot.

Also consider Audiokinesis.

With re: to the Ohms, without heroic room treatment, they aren't well suited for close wall placement.

agree with ohms.