One thing. Not sure how it affect performance but it causes deadlocks.

<?xml version="1.0" encoding="UTF-8"?>

-<deadlock>

-<victim-list>

<victimProcess id="process18ee4633468"/>

</victim-list>

-<process-list>

-<process id="process18ee4633468" xactid="156589641" waitresource="KEY: 5:72057594041991168 (d17c5d3ee874)" transactionname="user_transaction" trancount="2" taskpriority="0" status="suspended" spid="172" schedulerid="11" sbid="0" priority="0" ownerId="156589641" logused="7012"...