There are a few sensations you might detect:
1) The razor passes over the pad smoothly without a "drawing" or "ut-oh, I'm about to get cut" sensation. The razor is essentially dull for shaving purposes. Requires aggressive stropping or, more likely, honing.
2) The razor passes over the thumb with that "ut-oh" sensation, but there is also a subtle "gritty" or rough sensation at the same time. More stropping required, possibly on the linen with some pressure then back to the leather.
3) "Ut-oh" coupled with a sticky smooth "I'm-touching-a-friggin-laser-scalpel...whoa!" Absolutely no rough or grittiness detected. The razor is shave ready!