Been following your blog for a little while. Levelled to 70 mostly as retri but then raided as holy, have now switched back to retri. My understanding from your blogs was that I needed to try and get +hit and + AP, during last month prior to expansion picked up a few pieces as offspec drops and from badges.Unfortunately, I have not found an exact equation for ret stat comparison yet. The only precise numberrs I have for people are the basics on strength and AP. For the hell of it, here's the comparison:
Now slowly levelling in Northrend. Slightly confused by which items to take. Very few have +hit. Strength/AP comparisons are easy. But lots of items have either +crit, +expertise, +armour penetration. I have just started using RAWR to do item comparison but its not ideal, as trying to find the item you are looking at on the list can take lots of scanning, sometimes not there. How do you compare, +strength/AP/hit/crit/expertise/armour penetration? I used to have a basic formula in holy comparing intellect/Mp5/SP, do you have one for retri stats? +10strenght=+19AP=+3hit=+6crit for example?
+10 strength, after Divine Strength and Blessing of Kings, will become 12.65 strength. That converts to 25.3 AP.
So, for the purposes of gearing, 10 STR = 25.3 AP with BoKings (23 AP without BoKings).
For leveling, ignore your hit. Most mobs you face will be at-level, which means you'll just have the 5% miss-rate and mostly short encounters to deal with. For raid zones at 80, hit becomes a bit more valuable, but it has not conclusively been said by theorycrafters over at EJ just yet that hit to cap is top priority. Some spreadsheets and evaluation methods are claiming that strength scales damage quicker than hit at all times, even when un-capped.
What is absolutely sure, however, is that missing with a Judgement is bad times. You want to aim for hit cap if only to make sure you always land Judgement, as hitting with that ability ensures the mana refund from Judgements of the Wise and keeps the resources flowing.
So, in conclusion, here's what I think you should be aiming for -
Strength and Crit while leveling
Hit to cap for raids
Once hit capped, Strength > Crit > Expertise to dodge-cap > Armor Pen/Haste
It's not fool-proof, and it probably isn't exactly what everyone thinks the priorities should be, but it's a sound way to go about it that no one will call you an idiot for.
This is all assuming you aim to play in a raid environment. If your goal is heroics, things shift around a little.
My plan is probably going to end up being as follows: "When in doubt, wear the higher iLvl gear!" I'll download the latest Rawr eventually to figure out what's really best, the projections of that program are usually top notch.