I like the X series machines I owned two myself, let me check out the i5-6600u and the other processor, in general you don't need the i7 processor my own laptop is an i5 but my son's is an i7. I'll get back to you with thoughts before your morning.
I've checked the X260 is a 2016 model it doesn't natively support Windows 11 because it doesn't have the TPM 2.0 module, they've used the kludge to get round that in order to install it for you but you would/could have a problem if you ever had to reinstall Windows. The X260 has a 6th gen processor you would be better picking an X280 with and 8th Gen processor this link looks like a better bet although a fraction more expensive. Brand New Lenovo ThinkPad X280 laptop Intel Dual/Quad-Core i5/i7 8250u/8550u 8G/16G DDR4 RAM 256/512/1TB SSD HDD ROM Built In Camera/WEBCAM Business Ms office windows 11 PRO Ultra-thin 12.5 inch Screen class/learning Business notebook computer | Lazada PH edit: You need to be careful on Lazada to pick the correct configuration my link is to a 16GB 256GB configuration they're sold out of the 8GB configuration but honestly I wouldn't buy anything less than 16GB RAM these days. These devices perform at their maximum speed when plugged in on battery they are always a little bit slower. When my kids had their X230's I had docking stations for them attached to larger monitors and full size keyboards they rarely used them as stand alone laptops.
