I think I have my electrum server implementation feature complete.  More testing is needed.

You can help me by trying it out:

h.1209k.com:50001:t
h.1209k.com:50002:s

It is about 4k lines of java.  It syncs faster than the python reference server using multiple threads to import the transactions for a block.  It also works on the transactions for multiple blocks at once.  It uses a local mongodb instance for data storage, but it could use pretty much any fast key-value store.  It syncs the entire blockchain from scratch in about 3 days (faster on fast hardware+ssd).

In my testing, it seems to be faster to sync a large wallet (300+ addresses) about twice as fast but I haven't done rigorous testing there yet.

I hope to release the code later this week.

If you encounter problems and want to help track them down please reproduce them on:
h.1209k.com:50015:t

This port records all TCP traffic in and out for debugging purposes.  Then let me know the time you did it as exactly as you can and I'll be able to pull the logs.

FYI, if you want to connect to a single server and no other the command line looks like this:
electrum -1 -s h.1209k.com:50006:s