Considering how severe the diminishing returns are for the speed stat, I expect it will make practically no difference - click here for a chart using data from a 111. If anything, a 111 will have an easier time reaching the necessary secondary stat % to maximise the Longstrider trait while also using whatever non-socketed speed rating items they have.
If you do have the needed secondary stat % for Longstrider, then speed rating is likely slightly better on a 110, but the difference will be very minor (likely <1%, but we'd need to compare how 110s and 111s scale from the same speed rating).
You do need to keep in mind you only get legacy loot for draenor dungeons/raids at 111+ so if you want a speed char for farming xmog and what not you'd need to do 111