IE is frustrating.
We are currently using the 2.4 api with jquery 1.62 and jqueryui 1.8.14
I load it from a jsp page using
<script type="text/javascript">
google.load("earth", "1.x");
google.load("jquery", "1.6.2");
google.load("jqueryui", "1.8.14");
</script>
It works in ie7, ie8, and ie9. I only use ie7 developer tools, as my office will not allow me to upgrade, however we do test against ie8 and ie9 for compatibility and havent found many issues.
Hope this helps, or at least alleviate's some of your concerns.