Just found one thing I never thought about before. The adept power of increased reflexes seems to be the only initiative enhancing version that isn´t compatible with anything that changes initiative. Did I see that correct? No "Increased Attribute - Reaction" Adept power? No Biowarre? No cyberware? No reaction enhancers? Nothing?

Actually, Sinaptic booster (bioware) and Wire reflexes (cyber) say the same thing, yet Reaction Enhancers state they still give Reaction.

What I imagine this means is while you would get the added Reaction from Enhancers, spells, and adept powers, only the reaction gained from an ability/'ware that also raises your IPs adds to your initiative as well. The other Reaction is only used for other purposes (combat and driving, mainly).

For instance: +1 Rea/+1 IP (let's say Wired Ref. r1) and Reaction Enhancers r2 means the guy gets +3 Reaction for avoiding attacks and driving, but only +1 Rea for initiative purposes (since he got the +1 from the +1 IP as well).

Ex. 2: Wired Reflexes r2 with r1 Reaction Enhancers. +3 Rea for driving/avoiding attacks, with +2 Rea for Initiative.

Actually, it stacks with anything that increases Reaction that does not also have a limiter on it. What it does not stack with is anything that directly affects your Initiative or Initiative Passes, such as the Increased Reflexes spell (which gives a bonus to both I & IP), or any of the IP 'ware (Synaptic, Wired, MBW)

So is this another case of "bad phrasing"^^ Thank you very much.

Not really, reaction boosts are not initiative boosts. They indirectly raise initiative. Wired Reflexes and it's ilk don't stack with things that raise initiative.