How to insert/update siebel records using SWE API?

Hi,

We have a requirement where a mobile app tries to update/insert records in Siebel via SWE commands. We have found below Oracle bookshelf references where its documented how to achieve this:

Approach 1: App directly hits the Siebel server url with appended SWE commands

1) http://docs.oracle.com/cd/E14004_01/books/MoblConn/MoblConnWorkwSMC8.html

Approach 2: Send XML based requests

2) http://docs.oracle.com/cd/E14004_01/books/PortalFrame/PortalFrameDelConExtWebApps23.html#wp1009809

We have below questions related to these:

1. What are pros and cons of SWE API over webservices?

2. In approach 1,

a) Is their any limitations to the volume of data exchanged?