This is honestly a horrible keyboard.. the worst entry level keyboard logitech had ever made.. I could not last 20 minutes on it and the keyboard lifespan is terrible on top of that.. Also is not close to the feel of utlrax.. And WOW, these keyboards became expensive.. bloody hell...
@ponder, I have the USB ultrax premium, think yours may be the ps2 one.. anyway, I will gladly donate mine to you.. sadly my scissors on my space bar are no longer good.. other than that it is perfect.. In fact it has only seen a few months of use since I got it brand new.. maybe you can resurrect my space bar with spares from yours..?
Otherwise, I think the best Logitech alternative is this one: Has similar low profile keys as far as I can tell but, its pretty expensive..
https://www.logitech.com/en-us/product/illuminated-keyboard-k740?crid=27#specification-tabular
From what I remember, the Microsoft Wired 600 was very similar to the ultra x but, had a little bit of a softer action on the keys than the ultra x did..