I recently bought an IS250 again, as they are such good all round cars. My only gripe with my recent purchase was the very dim Halogen bulbs due to having the SE version of the IS250.
I did a lot of research and opted for some Philips Ultinon Pro3021 H11 LED bulbs that are 6000k colour temp, a decent white without being overpowering or 'bluish' which I've never liked. They cost £39.80 for the pair, which is fairly reasonable to me. They did have the 5000 series and the 9000 series, but you are looking at around £80 to £115 respectively. The lumens rating is higher on the model I've bought apparently, so that's the key reason for change and a proper beam pattern.
The main thing is it's got a decent beam pattern with the step down and I'll be surprised if it doesn't pass the MOT (as they are technically not road legal).
Overall, I'm extremely happy with them and I feel much safer driving with the newer bulbs in.
Pics below:
Wall pattern and brightness in the day time with one side done:
Comparison of each side:
Doesn't look blue at all in reality, it's just how the camera picked it up:
Comparison of before and after:
The night shots were too difficult to capture and make a comparison, but I'll see if there's some captures on my dashcam eventually.