How do you write model logic with NDB & NDBT (in Nette 2.3)

TL;DR: what's the best practice for handling model logic in NDB & NDBT, which would allow me:

• easily query and fetch rows from database with great and super simple NDBT syntax
• work with the same model representation in complex business logic

Longer version:
Hi, I've been traditionally working with Doctrine 2, where you define your model classes explicitly and then it's very easy to manipulate your rows / entities in your complex business model logic, and eventually save the changes, e.g.:

<?php
class MySuperService {
  // Approve objection to a change request, and update the change request accordingly.
  public function approveObjection(ChangeRequest $request, Objection $objection) {
    if ($objection->isOpen()) {
       $objection->status = '...';
    }
	if (...) {
       $this->updateRequestDeadline($request);  // possibly modifies $request->deadline and other fields
    }
    $this->updateWeight($request);  // more logic which updates $request
    $this->em->flush();  // save changes to db
  }
?>

On a smaller projects, I decided to use Nette Database (NDB) & Nette Database Table (NDBT), because it's simpler and you don't need to write so much code. It was in version 2.1, and my business logic looked very similar. Concrete model classes were replaced by generic ActiveRow:

<?php
class MySuperService {
  // Approve objection to a change request, and update the change request accordingly.
  public function approveObjection(ActiveRow $request, ActiveRow $objection) {
    if ($objection->status === 'open') {
       $objection->status = '...';  // works in Nette 2.1
    }
	if (...) {
       $this->updateRequestDeadline($request);  // possibly modifies $request->deadline and other fields
    }
    $this->updateWeight($request);  // more logic which updates $request

    // save changes to db
    $request->update();  // works in Nette 2.1
    $objection->update();
  }
?>

NDB and especially NDBT made it really easy to fetch data from database and pass it to templates. And it also allowed me to have complex logic in the business model.

However, when I tried upgrading to Nette 2.3, I noticed that this functionality has been removed.

That means I'd have to convert ActiveRow to an array or to my custom model class, process the business logic, and then save it back to the database. This seems very weird and schizophrenic to me – some code working with ActiveRow and some with different representation.

How do you handle model classes with NDB & NDBT? Do you sometimes use ActiveRow and sometimes another representation? Do you always convert to your representation? What's the best approach?