Have both, have used both extensively the past couple months. They have very different sounds and use cases. Vocal Bender is MUCH cleaner, and contrary to what you said, Little Alter Boy is MUCH dirtier...with a few features for more harsh sound design (i.e. the 3 modes + drive). However, Vocal Bender's modulation panel (+ waveform display) and note specific features make it far superior when doing pitch / formant automation. If I need to automate pitch- say C to F to G# - it takes 2 seconds in Vocal Bender because you can automate using notes (with root key), whereas Little Alter Boy you have to automate the pitch wheel, which can be a huge pain in the *****.
For example - this entire feature set doesn't exist in Little Alter Boy, and is extremely useful (timestamped): https://youtu.be/v50kOeJBTdQ?t=296
I like the sound of Little Alter Boy better (has a much grittier low fi sound...even in default mode), but much prefer Vocal Bender for complex automation. I really wish these plugins could be combined together, because they both have very useful features, and sometimes I want the sound of Little Alter Boy with the features of Vocal Bender (like amp modulation), and vice versa.