Cloud Poodll  and Classic Poodll both do very similar things. In fact most Classic Poodll plugins have a matching Cloud Poodll one. Cloud Poodll is newer and a better choice in most cases. However Classic Poodll has some merits which you may prefer depending on your needs. 

Poodll Essentials subscribers have access to both Cloud Poodll and Classic Poodll. So you can change from one to the other if you need to. 

Poodll Institution subscribers have access to Classic Poodll,  Cloud Poodll Assignment Submission and Cloud Poodll for TinyMCE/Atto, Poodll ReadAloud.

By Feature

Cloud Poodll
Classic Poodll
Plugin dependenciesnonePoodll Filter
File storagePoodll Cloud(AWS S3)Moodle data directory
HTML5 audio recordingyesyes
HTML5 video recordingyesyes
Flash fallback (non HTML5 browsers)noyes
Media Conversion(mp3/mp4)yesyes
Automatic Transcriptionyesno
Whiteboard toolnoAssignment/Question/Toolbar
Media playersnoPoodll filter
Interactive widgetsnoPoodll filter

By Plugin Type

Cloud PoodllClassic Poodll
Filter-Poodll Filter
Assignment submissionCloud Poodll Assignment SubmissionOnline Poodll Assignment Submission
Assignment feedbackCloud Poodll Assignment FeedbackPoodll Feedback
Question typeCloud Poodll Recording QuestionPoodll Recording Question
Atto Toolbar IconCloud Poodll for AttoPoodll Anywhere (Atto)
TinyMCE Toolbar IconCloud Poodll for TinyMCEPoodll Anywhere (TinyMCE)
Database Activity Field-Poodll Database Field
Repository-Poodll Repository
Activity ModulePoodll ReadAloud
Poodll WordCards
Poodll EnglishCentral
Poodll MiniLesson
Poodll Solo