I absolutely go with Autocomplete. See
- Auto Complete plugin 1.0.15 - Complete tiddlers, fields and your dreams - Plugins - Talk TW (tiddlywiki.org)
- Community Curated AutoComplete Triggers - Tips & Tricks - Talk TW (tiddlywiki.org)
It gives me tailored autocomplete. I use ?s maens autocomplete for only system tiddler. I can adjust filter to type only few chars of the last part of the name and it complete the whole long long long 
title
It always there in the tree structure! See below screenshot
