To OP glad your happy with your desision! The Z4 is one of the best cars you can buy IMO and hope you continue to enjoy it!
Have to say my dads 911 has cost less than my Z to look after since weve both had them. Both had major servicing, and the servicing and running costs so far the porsche has been cheaper, 57 997 Cs 15k, 56 Z4Mc 52k. Drive the Porsche nicely or on a long motorway haul and it easily gets 34-35mpg whereas you really have to try extremely hard to get the Z4M over 31mpg, obviously neither are designed for this but just an observation. But obviously if either go wrong the parts and labour are as expensive for both.
Although Porsche specialists are generally seen as the place to go in the Porsche community, unlike the BMW community most, including myself continue to have servicing carried out by BMW as that stamp is paramount. In the porsche world a specialist stamp is as valuable as a dealer as most are well known and highly respected.
In my mind I still prefer the Porsche to the beemer, but you have to get a good porsche as there are more problems especially with a pre 2001 996, similar probelems with late 996. 997 are better but still suffer from the similar problems, although less documented, unlike before they check the RMS seal as a matter of corse every time the car goes in, infact my dads was replaced as a matter of corse, not because there was anything wrong or it, (like leaking) but because its worth sorting, piece of mind, which is why there is less documentation compared to the 996. If your RMS seal goes on a 997 your car hasnt been looked after properly by the previous owner or you haven't taken the necessary steps to keep it running properly. You also have to keep an eye on it, many of the problems show no visible signs. If you do and have it regularly serviced and do plenty of milage in them they are bullet proof its when they sit and are garage queens problems start. There was an article I read recently based on the 996, was used as a race experience day for a significant period of time and not one suffered from RMS, simply because they were being used properly on a daily basis. But the M cars are very hard to beat which is why I ended up with one over a 996, they are certainly a big worry and I couldn't quite stretch to a good 997.
Its like anything if they are cheap... they are cheap for a reason. Documentation is paramount, history etc get a good one and have it checked over first and you will be golden or extremely unlucky. Would it put me off? No chance, its such a shame people scare monger people away from these cars. You just need to do your homework, like anything else. Horror stories will always be there, like the S54 blowing up... yet we rarely here anyone with this problem possibly 2 members? Yet there is plenty of documentation and scare mongering on the net.
BTW Kryton said it before but pwwhoorre! your 911 is absolutely stunning.
IMG_0600 by
tom_scott88, on Flickr
My Z with dads Porsche.