Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

I noticed Elixirs and Potions have no effect if you use them while using Tenser's Transformation. I don't know if it's intended or if allowing it would make Tenser's too powerful, but I thought I'd throw it as a suggestion.

I don't know what the state of Tenser's is right now with the changes to Spell Focus Transmutation, but I personally find it weird that you're just shooting yourself in the foot if you're a pure mage and cast it without those feats. Is it actually worth it to cast it with the feats or is the ASF just not worth it?

It also seems to me like it's a lot more beneficial to non-casters than it is for casters, which doesn't make a whole lot of sense.

Pretty much every manner of spellcasting (natural as well as 'simulated' through potions/wands/clicky items/etc.) is prevented from functioning while under the effect of Tenser's Transmutation. The AC bonus from Transmutation spell focus isn't applied either (just tested to confirm with my Augment Form/ESF: Transmutation character), as it is not a polymorph effect -- just a series of buffs that can allow for a properly-built mage, in their natural form, to compensate for their reduced BAB if they want to go for melee.

All that being said, a properly built gish can get great mileage out of it. In fact, my currently most-played character relies on it heavily in order to be able to solo content, as it gives him a +8 AB for a period of time that I'd simply want to be autoattacking anyways. What it does require to set up is an ability to do personal damage through martial means, and a reliance on the wide plethora of buffs an arcane spellcaster has available in order to avoid taking damage while it's being used. If you need to recover health in-between encounters, Healer's Kits work great in that regard, and the Taunt skill still works to debuff enemy AC further. In the case of an emergency it is possible to drop Tenser's using the Remove Effects PC Tools menu and then proceed to use the spells/items you need.

My one complaint about the spell is how Constitution EB stacking functions within the game's engine. If you do need to drop Tenser's during a fight, or it runs out of its own accord, you'll be taking about (your HD x 2) damage. As I don't feel this is an intended function of the spell effect, unlike the denial of spellcasting, I would personally like to see it changed. I made a Suggestion thread about it HERE.

I think you have three things going on in that post, and I can't really answer authoritatively on any of them (since my alchemist dosen't use arcane spells) but I thought I might offer some insight.

1) Per the spell "You lose your spellcasting ability, including your ability to use spell trigger or spell completion magic items, just as if the spells were no longer on your class list." AFAIK, this shouldn't stop you using UMD or "Use Activated" items like potions. This gets implemented in-game as "100% spell failure" which neuters UMD on scrolls and wands, but potions and elixirs not working seems definite bug.

2) No idea what bonus the feat provides, since it isn't listed on the wiki.

3) If the wiki is right (link) then it is identical to the P&P version (link) which isn't always saying much, but I think is reflective of the intent of the spell. Namely, it's a way for a wizard not to completely suck at an impromptu knife fight. Despite the claim, the spell definitely does not make you an "engine of destruction".

In effect, it uses magical buffs to give a wizard or sorcerer the same base stat-line of a fighter, in terms of AB, combat stats, and hopefully AC and proficiency. What it does not provide are feats or equipment - which in our paradigm count for a lot more than the base stats often do. Since the average wizard isn't carrying around full-plate and a great-sword he can't use, it only really makes sense to do so if you have this spell prepped. However, even when you do, you are still going to be 10+ feats behind the fighter in combat ability, and your +4 enhancement bonuses stack with nothing to give you that extra edge.

So, yes, it synergizes with non-casters better, because they have all the things that the buffs help with and no tradeoffs. Unfortunately, most of them can't cast a 6th level spell without 12 levels invested into a spellcasting class, so scrolls or Elixirs are the only practical way. The better way of looking at it would probably be looking at the spell as a combined Bears/Bulls/Cats/Barkskin with a few other unique benefits that primarily save you buffing time in exchange for a short duration and locking out other spells while active.

PNP gives BAB bonus, here it gives an AB bonus. It's a bad spell for pure mages and it seems like it's completely outclassed by the 4th level Polymorph spell if you go for Augment Form (again on pure mages).

However, if it's a significant buff for gish build then I guess I wouldn't touch it.