My first impression of Magic Fields is it is very easy to understand, very easy to use, has the features you would expect and the features behave exactly as you would expect. You almost do not need a manual, which is a good thing because the English documentation is not very good. This is very straightforward implementation of custom fields, custom post types and custom taxonomies which has the features you want, is stable and has a very shallow learning curve. In particular for me, the support of multi-valued simple fields was critical. Do not be turned off by the poor English documentation, since Magic Fields is very straightforward your best guess would probably be correct. The authors are from Mexico and they really have done very nice work but the English documentation is so bad I almost decided against it but I am glad I stuck it out. If you already understand WordPress custom post types, custom fields and custom taxonomies then this English example should help you get started.