reduce size of bicycle images in Tape vs. Tap analogy. see: #34 (comm…

…ent)

tap-advanced-testing.md

@@ -1,14 +1,54 @@
 # _Why_ Use `Tap`?
 
 In _most_ situations **`Tape`** will be _exactly_ what you need
-to write and run your Node.js (server-side) tests.
-**`Tape`** is minimalist, fast and has plenty of flexibility.
+to write and run your Node.js/JavaScript tests.
+**`Tape`** is minimalist, fast and has flexibility when you need it.
 _Occasionally_ however, the needs of the project
-require a few extra features of the testing framework.
+require a few extra features from the testing framework.
 
 
 ## Analogy: _Single_ Speed vs. _Geared_ Bicycle
 
-![sku-fixie-single-speed-bike](https://user-images.githubusercontent.com/194400/46041154-102cb800-c10a-11e8-8646-153a77b53408.jpg)
 
-![specialised-racing-bicycle](https://user-images.githubusercontent.com/194400/46041153-102cb800-c10a-11e8-9c51-3c16eb81db4c.jpg)
+<div align="center">
+    <a href="https://user-images.githubusercontent.com/194400/46041154-102cb800-c10a-11e8-8646-153a77b53408.jpg"> <!-- link to larger version of image -->
+        <img width="700px" src="https://user-images.githubusercontent.com/194400/47200839-8a4e0680-d36f-11e8-9419-96e8c0ca968e.jpg"
+        alt="single speed bicycle - perfect for short trips on fairly flat ground">
+    </a>
+</div>
+<br />
+
+**`Tape`** is like a **single speed** bicycle;
+lightweight, fewer "moving parts", less to learn and _fast_! <br />
+_Perfect_ for **_short_ trips** on _relatively_ **_flat_ terrain**.
+_Most_ journeys in cities fit this description.
+_Most_ of the time you won't _need_ anything more than this
+for commuting from home to work, going to the shops, etc.
+
+
+<div align="center">
+    <a href="https://user-images.githubusercontent.com/194400/46041153-102cb800-c10a-11e8-9c51-3c16eb81db4c.jpg"> <!-- link to larger version of image -->
+        <img width="700px" src="https://user-images.githubusercontent.com/194400/47200840-8a4e0680-d36f-11e8-8634-2fcf80eedee5.jpg"
+        alt="geared bicycle bicycle - for longer distances and hilly terrain">
+    </a>
+</div>
+<br />
+
+**`Tap`** is the bicycle _with **gears**_ that allows you to tackle _mountains_.
+
+
+> <small> **Note**: This analogy falls down if your commuting distance is far;
+you need a geared bicycle for the long stretches!
+Also, if you _never_ ride a bicycle - for whatever reason -
+and don't appreciate the difference between
+single speed and geared bikes this analogy might feel less relevant ...
+in which case we recommend a bit of background reading:
+https://bicycles.stackexchange.com/questions/1983/why-ride-a-single-speed-bike
+</small>
+
+# _Why_ NOT Use `Tap` _Everywhere_?
+
+
+One of the _benefits_ of Free/Open Source software
+is that there is near-zero "switching cost".
+Since we aren't paying for the code, we can