This is very seductive in theory, but in practice it does not work. The regional lists tend to dilute the constituency link of the constituency MPs in two ways. The constituencies would have to be much larger under AMS, in Germany often having as many as 300,000 voters each. Also, many constituency MPs are also on a regional list. Michael Portillo and (even worse) Neil Hamilton could have got back into Parliament through the back door created by the regional lists. It would become impossible for the electorate to kick out any MP whom the party wanted in Parliament.
The system which most effectively combines proportionality with the constituency link is the system used in Ireland, the Single Transferable Vote. Constituents can choose which MP in a multi-member constituency they prefer to represent them. MPs, and candidates from the same party are in competition with each other for the same votes. In the last four Irish general elections, two-thirds of the TDs (MPs) from the Fianna Fail party who lost their seats lost to other Fianna Fail candidates.
It is very difficult for the parties to control who gets elected, as there are no safe seats. The people of Tatton would not even have needed Martin Bell to remove Neil Hamilton - he would have been defeated by other Tory candidates in the same area.