If you are used to C on US airlines - sure, UL is fine.
But if you are used to proper C service - it's amateurish at best.
Example - people from Y coming into C cabin to visit friends (and it looks like everyone is friend of everyone), sit and stay in C for hours, disturbing paying C passengers. Not even an attempt from the crew to stop this.
Another example - a passenger reclining his seat, putting the sleep mask and headphones on and covering himself with a blanket is a fairly clear indicator that this passenger would like to sleep,right? Not for UL crew - you will be awaken and asked what you would like to eat

I have another examples, but the above ones should suffice. Again, it's a matter of perception - if you fly on UA or similar you will love UL. If you fly on EK/SQ/CX/LH/LX, even EY, the UL is amateurish at best.

Regards,

El Puerco Volante.