ReactivePropertyをINotifyPropertyChangedを実装しないクラスのプロパティと双方向同期させたい

通常であればコード（１）のようにModelがINotifyPropertyChangedを実装していれば、INotifyPropertyChangedの拡張メソッドであるToReactivePropertyAsSynchronized()を使用できます。

しかし、今書いているコード（２）は事情によりINotifyPropertyChangedが使用できません。
そのため、代わりにContentChangedというイベントを作り、それを元にModel→ViewModelへ片方向同期をするReactivePropertyを作り、さらにそのReactivePropertyの変更を監視してModelに書き戻す、という不格好なコードになってしまっています。

実際の動作は変わらないように見えますが、より良い方法があれば教えてください。

C#
1using Reactive.Bindings;
2using Reactive.Bindings.Extensions;
3using System;
4using System.ComponentModel;
5
6namespace ConsoleApp1
7{
8    class Program
9    {
10        static void Main(string[] args)
11        {
12            var model = new Model();
13            var viewModel = new ViewModel(model);
14
15            // ViewにBindingのつもり
16            viewModel.Content.Subscribe(x => Console.WriteLine($"ViewModel's Content was changed to: {x}"));
17
18            // Modelの変更
19            model.Content = "あいうえお";
20
21            // ViewModelの変更
22            viewModel.Content.Value = "かきくけこ";
23
24            Console.ReadKey();
25
26            /*  実行結果：
27                Model's Content was changed to:
28                ViewModel's Content was changed to:
29                Model's Content was changed to: あいうえお
30                Model's Content was changed to: あいうえお
31                ViewModel's Content was changed to: あいうえお
32                Model's Content was changed to: かきくけこ
33                ViewModel's Content was changed to: かきくけこ
34            */
35        }
36    }
37
38    class Model : INotifyPropertyChanged
39    {
40        public event PropertyChangedEventHandler PropertyChanged;
41
42        private string content;
43        public string Content
44        {
45            get
46            {
47                return content;
48            }
49            set
50            {
51                content = value;
52                Console.WriteLine($"Model's Content was changed to: {value}");
53                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Content)));
54            }
55        }
56    }
57
58    class ViewModel
59    {
60        public ViewModel(Model model)
61        {
62            // Model<-->ViewModelの双方向同期をするReactiveProperty
63            Content = model.ToReactivePropertyAsSynchronized(x => x.Content);
64        }
65
66        public ReactiveProperty<string> Content { get; }
67    }
68}
69

C#
1using Reactive.Bindings;
2using System;
3using System.Reactive.Linq;
4
5namespace ConsoleApp2
6{
7    class Program
8    {
9        static void Main(string[] args)
10        {
11            var model = new Model();
12            var viewModel = new ViewModel(model);
13
14            // ViewにBindingのつもり
15            viewModel.Content.Subscribe(x => Console.WriteLine($"ViewModel's Content was changed to: {x}"));
16
17            // Modelの変更
18            model.Content = "あいうえお";
19
20            // ViewModelの変更
21            viewModel.Content.Value = "かきくけこ";
22
23            Console.ReadKey();
24
25            /*  実行結果：
26                Model's Content was changed to:
27                ViewModel's Content was changed to:
28                Model's Content was changed to: あいうえお
29                Model's Content was changed to: あいうえお
30                ViewModel's Content was changed to: あいうえお
31                Model's Content was changed to: かきくけこ
32                ViewModel's Content was changed to: かきくけこ
33            */
34        }
35    }
36
37    class Model
38    {
39        public event EventHandler<string> ContentChanged;
40
41        private string content;
42        public string Content
43        {
44            get
45            {
46                return content;
47            }
48            set
49            {
50                content = value;
51                Console.WriteLine($"Model's Content was changed to: {value}");
52                ContentChanged?.Invoke(this, value);
53            }
54        }
55    }
56
57    class ViewModel
58    {
59        public ViewModel(Model model)
60        {
61            // Model->ViewModelの片方向同期をするReactiveProperty
62            Content = Observable.FromEvent<EventHandler<string>, string>(h => (s, e) => h(e), h => model.ContentChanged += h, h => model.ContentChanged -= h)
63                .ToReactiveProperty();
64
65            // ReactivePropertyの変更をViewModel->Modelに反映する
66            Content.Subscribe(x => model.Content = x);
67        }
68
69        public ReactiveProperty<string> Content { get; }
70    }
71}
72