The quality of the reader you use in your self taped auditions is important - look at who you are using and assess whether they are the best reader you can find or simply the most convenient.
You want someone who will allow you the freedom to do the scene the way you want without any forceful interference, but also add to the process by suggesting things to improve the read (within the boundaries of what you're comfortable with).
Above all - they need to be a great actor, because we are all better when we are opposite someone amazing!
Please don't settle for someone average and think you can 'make up for it'. We can all 'make it work', but isn't it better to have an equal (craft-wise) to help you make it amazing instead?