I upgraded my interior lights to LEDs this afternoon.
I'm very pleased with the clean white light of the LEDs. The X1 should come this way IMHO.
I replaced the stock bulbs with
Sylvania LED/Map Light Bulbs from AutoZone. I paid ~$8.99/bulb and replaced the 3 front dome lights and 2 rear "dome" lights (no need to replace the footwell lights since they are already LEDs). ~$45 was a significant savings over the BMW branded kit.