Thanks Brian,points that do make me want to put a little more thought into this. For now I will keep using my old racks. As for more ventilation I use a full screen inner cover in warm weather , it appears to help cure honey faster and I see less bearding even when the hives are up to full strength. This was the first winter I used slatted racks I had no winter losses. (27 out of 27) So maybe best I dont fix it. Thanks for the comments. Jeff :)