In EU update 0 ("mod 10"), the Invisibility spell was seriously strengthened because monsters no longer really aggro when you run close by them.
This made Invisbility a lot more powerful, and also shifted the balance between the two sources of stealth. A DDO character can obtain stealth by either of two means: either getting high skills in Hide and Move Silently and then activating the Sneak icon, or by having the Invisibility spell cast on him (optionally with Haste and Jump added in).
The spell-buff choice obviously makes no demand on the character's permanent build choices, while the skill-based stealth calls for not only ranks and ability bonuses, but also good gear and prehaps the exclusion of gear. Since skill-based has more of a cost in character dedication, it makes sense that it should provide better results; or at least similar.
But that's not what happens now. In the most common situations where stealth is useful, someone with Invisibility is a lot better; he's so much better, in fact, that characters with high stealth skills are basically better off to not even try using them, and instead ask for an Invis as well.
The cause of that imbalance is simple and obvious: the Invisibility spell allows you to keep moving quickly, especially because you can still jump. Look at a thin corridor packed tightly with Orthons in Sins of Attrition: it's literally impossible to get by in Sneak mode, but Invisibility means you can bounce right over the group.
Here are three ways to rectify this imbalance. All have been suggested before, but they are more important now that Invisibility has gotten so much stronger.
Suggestion 1
Characters are allowed to use Jump and Tumble while in Sneak mode. To do so causes a brief -10 penalty on all involved skills (meaning that if someone wants to Sneak-Tumble, he'll need 10 more points in Tumble, Hide, and Move Silently than if he were doing those actions separately)
Suggestion 2
Allow any character to attempt sneaking more quickly, with a penalty to Hide and Move Silently. How this can work is that Rogues gain bonus feats at levels 2, 4, and 6 for Sneak Faster I-III, and other characters can learn them by paying a small fee to a Rogue trainer.
Using those feats in place of the usual "Sneak" icon causes you to sneak at a higher speed, with a commeasurate penalty to skills. Sneak Faster III would have the biggest penalty, but let you move at 100% of running speed.
Additionally, the Faster Sneaking enhancements would be replaced with Improved Faster Sneaking, which reduce the skill penalties for sneaking quickly.
Suggestion 3
Allow sneaking characters to intentionally make noise. This can be an active feat taught at any Rogue trainer for a minor fee. Note that since the current DDO stealth rules lack this, there is the perverse result where a character with excessively high skills can be worse at sneaking, since he has no way to attract a monster to follow him without dropping stealth mode.