logo redesign for sliptree

so I won a logo contest at 99designs.com

I combined the leaf illustration and the initials S. so that it's easy to understand and easy to use in various media.

BRIEF :
Sliptree is a simple online invoicing service (SaaS) used by micropreneuers, small businesses and freelancers across the European Union.
We help small businesses get paid on time by providing enterprise-level tools to manage invoices, payments, and expenses.

BRAND NAME & MEANING
"Sliptree" is a combination of words "slip" and "tree", where slip can mean a payment slip or invoice and tree refers/symbolizes the software itself (ie a place to create and hold the invoices). The "slip" can also mean a different type of document, such as a price estimate or expense (incoming invoice)

CURRENT LOGO
The current logo is somewhat hard to understand, it doesn't work when scaled down to a small size (think browser favicon) and the leaves in the logo seems like an overused concept in our business. These are the issues with it.
However, I do like the fact that there is a logotype + logomark, which makes it somewhat responsive