I have flown a beautiful Aztec F and a not so beautiful older Aztec. They are very good twins with good range and carrying capacity. They have gentle handling characteristics.
Down side ? They are as ugly as can be and you wont impress the girls with your ugly nose and short stubby wings coupled to a stodgy out of shape body
Senecas? I have over 2000 hours in them. Just to clarify the 5 will way out perform the earlier versions in the climb. Expect a five to climb as well as a 3 or 4 at 20000 feet as the 3 or 4 do low level (yikes) Yes believe it or not the five will show 900 fpm in the high teens and 13000 to 1500fpm low down.
The five is turbocharged, wastegated and intercooled and can maintain full power. The earlier ones are limited in that way.
The five will fly engine out at 16500 feet which is impressive. Climb it high and you will see over 210 kts TAS. I have flown them all over Europe in all kinds of weather day and night. They are faithful servants.
It really depends on your budget? a five is muchos dollars the earlier senecas comparable to the AZTEC. Both are good twins.
Pace