My understanding is like this
- Hosted pabx is teh same as haveing it onsite - it just lives in a data centre - full functionality
- centrex is where you lease extensions off of a shared pabx - like having a home phone from a carrier
- effectively all home phones are centrex phones if there are 10 houses in your street connected to same carrier they are probably all on the same exchange( pabx) . The feature set is normally much more limited as you are using shsred resources.
if you need full pabx functionality get yoruself a hosted pabx and you can do wheat you want , if you only need basic functionality centrex will be cheaper
If I never did anything I'd never done before , I'd never do anything.....