I've had several car seats now, its a continuous problem getting one that suits you. My misses is on pram number 3 and all 3 have not been cheap

I have a mk4 golf 1.8T and that has isofix, I've used isofix and non isofix seats. I can say isofix holds better being a permanent fixing point but I wouldn't say it is safer than non-isofix seats and bases, as both have held well from experiences, as without isofix once the seat belt is on and locked there is little movement anyway.
In the childs younger months a seat with a base is handy as its a clip in clip out job, saving you a lot of hassle and time, even some buggies come with adapters allowing the child car seat to be fixed on. As they get older and require the higher group seats which last much longer, the base problem seems to go away as you tend to have the seat permanently in the car finding no need to put it in and remove it constantly.
Babies are recommended to weigh 9kg till they should even be front facing.
I've had two recaro seats and to be honest I was let down, they are very cramped for the child and seem to outgrow very quickly due to lack of space. Which is a shame as the child always felt trapped and limited in room to move and my daughter is not huge or fat like some babies, she's a nice size. I could understand if she was quite a big child but she's not.
I have found maxicosi to be very good however.