Yes to the diminished value claim. I've made the claim a few times. On any newer vehicle you should make a claim if you're not at fault - sometimes even if you are. In some states it is mandatory for the insurance to offer it on certain vehicles that are new enough.
If it's a major repair - have it totaled if you can in any possible way. As was said - it'll never be the same. There is no body shop on earth that can recreate a Toyota OEM assembly and paint process. It simply does not exist. And that's just the paint. Mechanically, it'll never be put back to new type condition. I hate to say hire a lawyer - but sometimes it's the best option. I'm a lawyer and I speak from personal experience in letting a dealership do a $22,000 repair to my IS250 that they basically ruined. It was never the same - not even close. And it didn't even need any body work or mechanical - that was just replacing the interior that was damaged. (Not a Lexus certified repair shop - just a regular dealer who basically took advantage of my trust that they could do a quality repair.)
Seriously - call a few local lawyers. Find one that you feel good about. The first calls don't cost anything. If they say it's going to require a huge deposit - run away. If they ask for 30% - run away. There are instances where both of those are perfectly reasonable. This is not one of those cases. It should take no more than maybe 2-3 hours of time before filing a complaint for the attorney to review your information and basically threaten the insurance company. Maybe an hour more to actually file the law suit - it almost never proceeds past that point. Once an insured person gets served they get on the phone with the insurance company on their end and things get sorted out PDQ. IMO $1500 should be at the higher end of what this should cost up to that point. I would guess $750ish. Before you hire a lawyer - talk to the insurance adjuster first and tell them that they have a specific date by which to make a decision - maybe 30 days out. If you haven't gotten what you're asking for by that date you are going to proceed with hiring your attorney to sue the driver of the other vehicle. Usually that's enough to get a fair settlement without actually having to file anything. If you have to - go ahead and proceed with the attorney.
Also - for the love of god - don't go to service king or any similar shop that's verified or whatever by the insurance company. Find a Toyota factory authorized repair center. They're night and day better and they won't compromise on the quality of the repair because Toyota's certification means something in this case. It's very specific about repairs and prohibits all the shortcuts that other body shops tend to use.