I haven't driven the X3 much yet as I only got it last Friday and also it's my first experience of owning a 4WD of any description but I've owned and driven BMWs for the last 35 years. You can see
some of my past cars here (if you're interested) and also in the Gallery section of the same link (It was my hobby website but recent health issues mean I've had to give up my hobby):
http://www.bmwclassics.co.uk/
So, impressions of the X3 so far...
It's very light and airy compared to other BMWs that I've known. The ride is a bit 'jiggly' but nowhere near as bad or harsh as some reviews I watched online lead me to expect. I suspect that this is possibly due to the fact that my E83 is only on 17" wheels and not on Bridgestone Runflats (it's on Pirelli Scorpions). The simple fact is it's also just higher than cars I'm used to.
It's also quite light and easy to drive...I don't notice too much torque steering or even pulling from the front wheels . It doesn't feel too different yet from a pure RWD car to me.
I haven't really tried to drive it fast...not why I bought it really but the N52 engine pulls it quite 'strongly'. I'm used to this engine as I have it in my Z4 3.0Si and it's a great engine! Loads of power and torque yet actually quite frugal for this amount of power. On the (slow) drive back from Harwich where I bought the X3 to Lincolnshire, it achieved 31 mpg. We had a bit of an afternoon out in it yesterday (mainly A-Roads) and I got 28 mpg. This seems about right to me as in the Z4 last summer on a trip to Switzerland we got low 30s mpg without hanging about on French motorways...but obviously the X3 is a heavier and less aerodynamic car.
For the past 4 years I've been driving an E38 728i Sport as my daily driver which is obviously a very different car to the X3. I'd have to say that obviously the X3 is a much less refined drive and also that despite its power advantage over the E38, it would be (in my hands at least) nowhere near as fast a car point-to-point. Once up and running the E38 Sport just handles so well and inspires more confidence at high speed. A shame that that's one of the cars that I now have to sell!
http://www.bmwclassics.co.uk/gallery/in ... 728i_Sport
Regarding the Z4s. I actually own three: the 3.0Si, a Z4M and an Alpina Roadster S.
In one sense the drive how one would expect from looking at the paper statistics. That is, in terms of speed the ranking is 3.0Si to Alpina to Z4M. However, my experience is that there are some unexpected anomalies:
Before I got the Alpina and Z4M (I bought them on consecutive days!) comparisons that I read and watched on YouTube put them as very close together despite their relative power differences (300 vs 343 bhp). I'm sure that on a public road, driven at full-tilt under those circumstances by a skilled driver, there is little to separate them. But, to the average Joe, when you get in the Z4M it feels instantly faster! You can really feel those extra 43 bhp straight away. Its steering etc. just feels more performance focused.
The Alpina is just so pretty though!

)
That said, actually the nicest to drive is the 3.0 Si. Despite 'only' 265 bhp its gearing is such that it is VERY fast of the mark and fast enough on normal A-Roads or twisty bits to make me think you'd have to be a very good/brave driver to get away from it in ether the Alpina or Z4M! I think its 0-60 is something like 5.6s! It also feels the more comfortable and compliant (once I got rid of the Bridgestone RFTs). It's also bar far the cheapest to run! Shame I've probably got to sell that too now!
http://www.bmwclassics.co.uk/gallery/in ... i_Roadster
I don't have any decent photos of the Z4M (I've had a bit of a difficult year with health probs etc) but here's one of the Alpina. I believe it's one of only 5 ever made in this colour (Toledo Blue):
