Based on item rarity (Not stats/effect/overall likeness) You have a better chance finding 2 Windforces before a high rune above gul.
There really is no "Rune Hunting" except for hellforge/countress. Other than those two places, it is going to happen to you by pure luck. Since (Other than those two places) you are not guaranteed any rune will drop. But are guaranteed items will drop.
Besides 1.11 items, I have found basically every uniqe item in the game. Only item I can think of (I'm sure this isn't the only one) that I know for a fact I have not found would be tyreals armor. Also just remembered never finding Death Fathom.
Iv found three Griffons eye's. Around 7-8 windforces, Well over 15 spiderweb sashs. A handfull of mara's ammy's (Under 7 id guess),probably around the same number for sojs. Approximatly 8 or so Tals armor's, and somewhere 3-5 of each of the grisswold set(Obviously meaning all but the armor) which are some of the not so common droped items. (Note, I ran bots in 1.09 and 1.10.
Common items would be included as like shako,Stormshield, Shaftstop, Skullders, Wizspike and things of that sort which Iv found more than I'm willing to take a guess upon.
After all that, I have found 1 rune above gul (Having the monster drop it) which was OHM (from Meph). Not to say people havn't found more High runes than I have rare items. But going off my example, you should see that by doing MF runs, you could trade the drops and get more runes, than waiting for a HR to drop.
Iv gotten numerious Um/Ists from monsters. But above gul, only that one.
If your on ladder, kill countress + upgrade. Mf + trade.
If your going for all "Legit" your not going to have an enigma for a long long LOOOOOOOOONG time.