It rained hard on Tuesday. I stood in my tiny kitchen. I craved hot and salty fries. My old oven took too long to heat. I bought two new air fryers to test, and here is my real story.
Ninja SP101 Review

I bought this air fryer to save space. It flips up when you are done. This neat trick blew my mind.
Pros and Cons
Here is a quick look at the good and bad.
| Pros | Cons |
| Flips up for easy storage | Tall foods do not fit well |
| Has a drop-down crumb tray | Gets very hot on the top |
| Preheats in just one minute | Wire trays are hard to wash |
Two Months With The Original Flip
I used this oven for two full months. I fell in love with it fast. I use it every single day for toast. The fan sits on the side wall.

This gives it a wide and short shape. My kitchen smells like fresh baked goods now. It makes the best crispy chicken skin. Do not try to roast a whole bird, though.
Recommendation
This machine is perfect for small spaces. It is great if you mostly cook flat foods. It is not good for bakers who need deep pans.
Ninja SP151 Review
Later, I bought the newer model. I wanted to see if it fixed old flaws. It looks almost the same outside. It has hidden changes inside.

Pros and Cons
Let us weigh the good and the bad parts.
| Pros | Cons |
| Deeper space on the inside | Harder to clean the bottom |
| Great clear digital display | No easy drop-down door |
| Very fast air frying time | Fan takes up rear space |
Eight Weeks Cooking With The Upgrade
I tested this newer version for eight weeks. Ninja moved the fan to the back wall. This makes the oven much deeper inside. I could finally fit my favorite baking pan.

The food still gets a loud, bold crunch. The hot fries tasted golden and perfect. Cleaning the bottom made me very mad, though. Without the drop-down door, I had to scrub blindly.
Recommendation
This model is perfect if you bake deep dishes. The extra space is a huge win for big pans. It is not good for cooks who hate tough messes.
Detail Comparison for Ninja SP101 Vs SP151
It is time to put them head to head. We will look at five main areas. Let us see which oven wins.
Capacity & Size: Ninja SP101 Vs SP151
Both ovens flip up to save room. The older model is much wider. The newer model is much deeper.
| Feature | Ninja SP101 | Ninja SP151 |
| Fan Placement | On the side | On the back |
| Inner Shape | Wide and shallow | Narrow and deep |
| Flip Storage | Yes | Yes |
Rating: Ninja SP101: 9/10 | Ninja SP151: 8/10

Cooking Performance: Ninja SP101 Vs SP151
Both ovens give a crazy good crunch. They handle hot fries and wings like true pros.
| Feature | Ninja SP101 | Ninja SP151 |
| Food Crunch | Very high | Very high |
| Heat Spread | Even on sides | Even in back |
| Best Food Type | Flat foods | Deeper dishes |
Rating: Ninja SP101: 9/10 | Ninja SP151: 9/10
Ease of Use: Ninja SP101 Vs SP151
The buttons are very simple to press. The smart screens light up bright and clear.
| Feature | Ninja SP101 | Ninja SP151 |
| Controls | Simple dial | Simple dial |
| Preheat Time | 60 seconds | 60 seconds |
| Flipping Motion | Smooth and light | Smooth and light |
Rating: Ninja SP101: 10/10 | Ninja SP151: 10/10

Cleaning & Maintenance: Ninja SP101 Vs SP151
This is where they feel totally different. The older one opens up at the bottom.
| Feature | Ninja SP101 | Ninja SP151 |
| Bottom Panel | Opens for washing | Fixed shut tight |
| Crumb Trap | Easy to reach | Hard to reach |
| Scrubbing Effort | Very fast | Takes more work |
Rating: Ninja SP101: 9/10 | Ninja SP151: 5/10
Cooking Speed: Ninja SP101 Vs SP151
You will never wait long for your food. Both are blazing fast compared to big ovens.
| Feature | Ninja SP101 | Ninja SP151 |
| Toasting Speed | Lightning fast | Lightning fast |
| Air Frying | Quick heat | Quick heat |
| Overall Time | Cuts time in half | Cuts time in half |
Rating: Ninja SP101: 9/10 | Ninja SP151: 9/10
Conclusion
Both of these neat ovens changed my life. If you hate cleaning, stick to the older model. If you bake in deep pans, grab the newer one. You will love how they save space!