Originally Posted by
omnipot
To the OP, I used to be a blood DPS myself and had a lot of the same questions/experiences you are having. Here's the decision I initially came to.
I switched to Unholy. lol
In cataclysm, Arp is going away as is Blood DPS. Strength will be your primary stat for AP. Unholy also out DPS's Blood in the current patch anyway.
To address your initial question, Strength will give you more of a DPS increase than Arp. As noted by previous posters, the difference is small (as you demonstrated in your illustration) , but it will out perform Arp stacking until very high levels.