Excluding the stargazer (that has it's unique defensive roll over the Drow noble) these subby are worse in every way to their BUR counterparts.
Perhaps they could have a more significant differences than their upgraded counterparts that allows more diverse builds, here a few ideas:
Stargazer -> Get Spell focus Evocation instead of Spell Focus Divination (allowing more flexible cleric and wizard builds without favoring PMs. This also allows druid builds as no other UR subby is currently good for these)
Battle Rager -> Throw in a (E)SF intimidate to help with pure barbarian builds, as their charisma is really abyssal.
Doppleganger -> (E)SF animal empathy would be a suitable small buff as it it affect shifter very slightly and helps to offset the charisma penalty.
I can't say for Battle Rager but there are lots of toons out there using Stargazer and Doppleganger. The real question is are then their BUR counter parts too powerful. I would nominate Anarch as potentially over powered but I think it is fine. Howler isn't a highly sought after sub so I would say that it is too powerful. Drown Noble is sought after but thats in part to the fact it is a new sub and also the up until now the BUR options for building a Theurge were limited and took considerably more creative thinking. The bottom line is that BUR should noticably outclass a UR that tends to be the trend between UR and BUR items.
@ Howler: This one is not the most sought after subby. In fact, even after recent tweaks, it is still somewhat worse than other BURs. In order to be more on par with them, -3 cha would have to be eased to -2. In no way is Battlerager "completely outclassed" by Howler, not even almost.
@ Stargazer: You said it yourself. Defensive roll is unique and in many people's eyes it puts Stargazer in the same line as some BURs. It allows rangers, AAs, monks and others to have free Epic Dodge, and you can bet such toons are running around (I actually downgraded my AA from Undying to Stargazer for this very reason and would not change it back). If you are looking for the penultimate theurge subby, you are right; but if you look at other creative options, not so much.
@ Doppleganger: Stats, feats, all this makes Dopple inferior to Anarch, that is true. But again, their unique feature of having any looks imaginable makes lots of people choose them before Anarch for their builds. Just look at Shakua's famous CoT, CS rogue or "KE's Spoliated Ichor" threader (has this one ever come to live? )
So, it is mostly the unique features that make people play them. Paper says URs are weaker than BURs, definitely. But oh my, that is the very difference between the two categories, is it not?
Yeah, looks like u can cs anythin non crit imm. - Big Crit