I just had some work on my E39 done and got the chance to drive a 2019 x1 28i. Made a quick review video on it here, if the E53 guys are interested:

https://youtu.be/0_o83KetEYY

My wife's 2005 X5 3.0i is just hitting 175,000 miles and going strong. It's due for a set of tires and front brakes, oil change. Some oil pan dripping. It is pretty tempting to start to look at a replacement but the X1 is not it, in my opinion.

It sure is nice to get back into the E53 after driving the X1. Totally different feel.