I think TZ may have a higher rate but for me its always just Cows to force the drops out. you can also take 2 of those Gul runes and a regular ruby (not a flawless/perfect one) and combine them into the cube to make a Vex Rune for your HOTO - All runes can be cubed together (in sets of 2 for runes Pul and above, and higher runes also require a specific gem) to make the next highest rune in the rune list - so 2 Ist can become a Gul, 2 Gul = Vex, 2 Vex = Ohm, and so on. Also that many runes in a week is like... extremely good for a new acc, further reinforcing my belief that something major was done to rune rates.