I have a Lumia 928 running WP ver 8.10.14157.200 via Developers Preview. The first version of Opera I installed crashed on loading. I rebooting my phone, but still have the same trouble and in fact the phone seemed to be lagging a bit each time I woke it. I just installed the most recent release of Opera and still crashing upon start up. Haven't had it on the phone long enough to see if the phone's overall performance is suffering still.