anyone have experience with "replacement cost" insurance, and Allstate?

We have a system valued at ~ $250k retail, and have our homeowner's insurance covers our system as part of house contents. We did NOT take out a seperate rider for our system.
Our homeowner's policy provides coverage up to ~ $15k which is based on a percentage of the value of our home and our policy that insures it. Additional coverage would require a seperate "rider" on our policy (ie - supplemental insurance).
We've experienced 2 claims in the past 20 plus years, both with close lightening strikes (we live in NJ near the shore) and our insurance covered our equipment repairs both times - on both occasions it was to our digital front end gear.
On both occasions, our equipment was send to an authorized repair facility and this facility worked directly with the agent to ensure our equipment came back to use in good working order.
I would be remiss if I didn't thank our insurance agent, who handles the insurance for all our properties. We have very good coverage at reasonable premiums. I feel insurance is cheap peace of mind and am very grateful to our agent for making sure my family and I are properly protected. Big thank you Todd (our agent's first name) :-)

You've received a lot of good advice so far from insurance industry professionals. I had a lightning claim myself many years ago that damaged (repairable) a few of my audio components, plus a laptop, printer, microwave oven, alarm system, etc. So, here's some additional advice:

1) Think of an insurance company like the IRS, meaning the quality and.or quantity of your claim documentation is essential to a having smooth and satisfactory outcome to your claim. Whether this involves the repair costs or a replacement quote(s) for a current model that meets the "like, kind and quality standard," if the item can't be repaired.

2) The above (# 1) is why it is so important to keep your purchase receipts, owners manuals and original boxes to document what you had.

3) Depreciation will not be applied to a repaIr; but, it will be applied to replacement of an item. Some insurance carriers have discretion to not withold the depreciation if the amount is low enough, because it is not worth their while to re-open a file just to issue a check for $100 - 200. But, if the replacement cost of the item is considered "high dollar," then they'll likely withold the depreciation until you've provided proof that you actually replaced the item at or near the current replacement cost amount that you provided them and had previously documented.

 Based on experiences of friends and family I would not trust Allstate for any insurance matter my personal opinion. 

I looked into getting coverage for my system a few years ago. State Farm, Geico, Chubb and Farmers. They all said that my system had to be on a rider that needed to be substantiated by their appraiser who was brought on by the adjuster. Long story short -  They were all were clueless on how to evaluate a audiophile system. The cost of the rider proved to be prohibitive.