It's OK
I stayed at the Westin LAX for 2 nights and went back for a 3rd night a few days later. 
Typical airport hotel - but ask for a room that overlooks the city (rather than the airport) if you want the quietest rooms. It's a huge hotel - so big lobby and kind of impersonal, but this is typical of airport hotels in the area so doesn't stand out for or against it. Parking is rather expensive both for valet and self-parking, so be prepared (although I should note that it's expensive everywhere in LA). The hotel does offer a shuttle to/from the airport, which is convenient.
Upon check-in, I was given a room on the 7th floor that reeked of cigarette smoke, and the hotel quickly gave me another room after I called to complain. the next room was just a few doors down and also smelled of stale smoke, but i should disclose that I have a sensitive nose and that I got used to it after about 15 minutes. I also suspect someone was smoking in a room down the hall (the entire property is supposed to be non smoking), which pushed smoke into the air vents and which could have been the cause of my problems. 
The rooms are large, and of course equipped with the Westin heavenly bed (admittedly the reason i chose Westin over the many other big-chain hotels in the LAX airport area). For my business travel needs, it was fine - quiet (didn't hear any guest room noise at all), comfy bed, comfortable working space, wi-fi available in the rooms, personal coffee maker and Starbucks coffee, plus wake-up calls that actually happen on time. Two things that were lacking in my humble opinion, were glassware (the cups in the bathroom were plastic cups) and a bathrobe.
For my second stay, I was given a room on the executive floor, which only had three things my first room didn't:
1) it was on 11th floor as opposed to 7
2) it had mouthwash (in addition to the usual shampoo/conditioner/lotion/shower gel)
3) there was a robe in the closet 
Also, had a hard time cooling the room during my second stay, though didn't have any issues in my first room.
It's definitely an older property and is probably due for some updating. Bathrooms are old-school - the tile was the small 4-inch variety rather than updated big pieces you see in updated bathrooms, and it was a small tub fitted with extender round shower rod to make it feel bigger (not oversized tub). Wasn't a problem - just wasn't impressive - all was functional. 
The only mystery of my stay remains the New Balance fitness gear the Westin now says they'll provide upon request...I am intrigued, particularly because carrying gym shoes takes up tons of space in my luggage, but the picture of the woman wearing skin-tight white pants and pajama-like top in all of the advertisements scared me from trying it, as did the concept of borrowing tennis shoes that who knows how many people have sweated through during their workouts. So - alas - I cannot tell you whether that's a pro or a con. Maybe I'll work up the courage next time.
If i'm flying through LAX and need a hotel close by the airport, I'll probably stay again - but it will be because I'm a Starwood member and I like the heavenly bed, rather than because the property was particularly noteworthy.