I'm considering the purchase of a Ceramic Totem of Xegony that has Spell Haste IV focus effect (15% spell haste).

Does anyone know if that focus effect would "stack" with the Cleric spell "Blessing of Reverance", which gives you 10% spell haste?

I think there is a 20% spell haste cap. I'm wondering if both of the above, combined, would take you to the 20% cap, or would it leave you at 15% given that the total of the focus effect and the spell would exceed the 20% cap.

Any info appreciated.

They do stack. I don't know anything about a cap though.

The cap is 50%, not 20%. There are a number of focus effects that gives more than 20% spell haste by themselves. Look at Affliction Haste for example (33% spell haste on dots).

The cap really only makes a difference when you have spell haste from AA's. This stacks with both spell haste focus effects and Blessing of Reverence. Quick Evac 3, for example, gives you 50% spell haste on evac spells by itself; focus effects and Blessing of Reverence stack with Quick Evac but won't take you past the cap of 50%.

Yes, it's a 50% cap. It's the same deal with Quick Buff AA -- once you hit 50% casting time reduction, it won't go down any more with items or spells. If memory serves, with stacking buffs/items, the effect is purely additive, so you just remove that percentage from the base cast time for each effect to get your total.

There is also a min cast time of 2.5 sec on spells greater than 2.5 sec.

For those of you that blast a lot, I've found stacking our 10% AA plus blessing of reverence plus spell haste 4 to be a lot of fun and great DPS (well agro too :-)

I haven't found that to be the case, Kineada...I've gotten my Nature's Infusion cast time from 3.8 seconds down to 2.3 seconds with Nightcaller Leggings (30% beneficial spell haste) and Blessing of Reverence (10%).

The limit is that you can't have spell haste effect spells who's cast time is less than 3.0 seconds.

Actually, that's not entirely true either. Most spell haste effects do have a minimum base cast time of 3 seconds. However:

Spell Haste I works on spells up to level 20, and has a minimum cast time of only 1 second.
lucy.fnord.net/spell.html...ource=Live (http://lucy.fnord.net/spell.html?id=2339&source=Live)

Spell Haste II works on spells up to level 44, and has a minimum cast time of only 2 seconds.
lucy.fnord.net/spell.html...ource=Live (http://lucy.fnord.net/spell.html?id=2340&source=Live)

So if you have low level spells with short cast times, and you want them to be shorter, Spell Haste I or II might be helpful. (Ok, so it's a bit of a stretch...) The only practical use I can think of is AE stuns for an enchanter, which can be situationally useful even at high levels. Spell Haste I should drop Color Flux (ENC/4) from 1.0 to 0.9 and Color Shift (ENC/20) from 1.5 to 1.3. Spell Haste II should drop Color Skew (ENC/44) from 2 to 1.7.