This works great. Thanks eComlabs.
Can anyone tell me how to do this via my_changes addon??? As everytime I upgrade the theme I lose the edits.
You can just disable default Description and Product features tabs. Then create custom tab, add HTML block with SMARTY support and specify this code:
{if $product.full_description}
<div {live_edit name="product:full_description:{$product.product_id}"}>{$product.full_description nofilter}</div>
{else if $product.short_description}
<div {live_edit name="product:short_description:{$product.product_id}"}>{$product.short_description nofilter}</div>
{/if}
{include file="views/products/components/product_features.tpl" product_features=$product.product_features details_page=true}