Features
Multilingual website supported typo3 extension.
Easily configurable with flexform, global variables in typo3 Extension Manager or by editing typoscript setup and constants.
Standard typo3 coding i.e. strictly follow available API ... like each html template used in that extension must be editable and accessible from fileadmin.
Integration of captcha, sr_freecap, xajax, ahmootools for any extension.
Integration of customizable RTE in front end i.e integration of RTE in content creation or editing from front end of typo3. That RTE can easily be configured by pages TS Config.
Quality and Maintenance
Code must not be time absorbing to execute. For this database tuning ans well as coding logics and code length and times of database access and database read plays a vital role. I take care and analyze code logic and work flow.
Maintenance depends upon clients requirement. It can vary 1month to years. So it wont be a problem in a way it'll be fruitful to the client as well as me to keep my work standard as well as long term relation.