Is it just my concern, that the ghosts from "Street Magic" are ways more powerful than the good old elementals? The new ones all have the skill "counterspelling" which is an huge advantage agains magicians and some innate spell powers. This ability alone makes this types of spirits absolutely horrible to fight.

Yeah.. the plant spirits are ok. But the Guardian spirits outperform in combat situations VERY clearly and are insanely versatile (Weapon skill of choice on rating of force AND magical guard? holy...). And the damn Ancestor-spirits can use divination (like the metamagic) at will with a high die-count. (So with every aura they can see and some good formulated question it is very easy to destroy some need for legwork/observations and can get the runners on the case of something which has yet to unfold)

What annoys me is that these spirits were added after the two major traditions were introduced; Hermetics and Shamans don't get them. Which means that creating your own tradition becomes that much more attractive.

It makes the common spirits virtually useless, that is more of my problem. And the new ones aren´t limited to possession traditions, that can really become a mess if you have to deal with them. these buggers are mage-killers par excellence.

If you think that the Common Spirits are Useless, then I would say that you are not using them correctly... there are traditions of magic that do indeed have access to these types of spirits, though I would say that no tradition has access to all of them, as that would be pretty abusive... and there could be a Lot of variation in "Hermetic" and "Shamanic" traditions that would allow replacement of one (or even 2) type of spirit for another... if a customized tradition replaces their spirits with the most optimal choices, however, I would say that something is wrong with the tradition...

For Example, even the tradition most associated with abusive power mongering (in traditional modern outlooks anyways), Black Magic, with their supposed trafficking with Demons and so forth, uses the traditional spirits... they did not even gain access to the "Specialized" spirits...

Hell... taking a look at the additional traditions provided in the Street Magic book, even they do not have complete optimization of the new spirits, because that would not really make a lot of sense...

Aboriginal... Guidance and Plant
Aztec... Guardian
Buddhist... Guidance
Christian Theurgy... Guidance
Druidic... Plant
Islamic... Guardian
Norse... Guardian
Path of the Wheel... Guidance
Traditional/Hedge Witchcraft... Plant
Voodoo... Guardian and Guidance
Wiccan... Plant
Wuxing... Plant and Guidance
Zoroastrian... Guardian

Single or double replacement would be okay in my book, as long as the tradition contained a solid, good concept and could stand on its own... if you are re-skinning a tradition using new spirits, and the same fluff to account for those different spirits, then that would be a red flag to me... but then again, custom traditions do take a lot of work to make plausible and workable, at least in my opinion and you could flavor almost any of the ones provided and just use what is out there already, by describing your spirits any way you like (while keeping the same basic spirits)...

Just my 2 Nuyen...

Keep the Faith

Yes, the Street Magic spirits are for the most part better than the old spirits (with the possible exeption of man, which is roughly comparable).
In fact, a lot of the gripes leveled at "too powerful" possession mages are really about the voodoo traditon being too strong thanks to getting the best possible spirit set-up possible.
Even if you'd get to choose all your spirit types yourself, you'd chose those (the only arguable difference would be taking plant instead of water, but that's kinda subjective).

Minor correction: Voodoo has Guidance, Guardian, as well as Task and they also have Spirits of Man. So 3 replacements and arguably the best BBB spirit type.

Yep... I stand Corrected... Not sure how I missed it, but I did indeed...
Sorry

Keep the Faith

I don't tend to view Shamanism as one of the 'big traditions' but then I also don't tend towards games set in western North America or Siberia. It's a localized tradition much like most of the others.

I find that the Task spirit is one of the biggest pain for one reason - Technical skill:
- Need Demolition ?? Got a spirit to do this with 10 dice
- Need to open that old lock ?? Well I'll summon a spirit with Locksmith

Last game the players knew they had to go through a safe. I had to DM rule that the spiriti would not be able to get the proper skill to open it. Okay, they still used that spirit with Demolition, but at least this attracted attention ...

Houseruling in this case is strongly recommended, but it doesn´t change the imbalance we are discussing. No matter how you use your spirits, that the new ones are better is a fact based on their skills and abilities, not of the orders you give them. The only old spirit i would use is an elemental with energy aura, but even this ability doens´t make the cravasse smaller.