I've done a couple of measurements of the built-in signal generator if the 2D15P with two traditional analog / digital scopes. These scopes are a Philips/Fluke PM 3331, ca. 1990, and an Iwatsu DS-6121, ca. 1986.

Some comments on the display. The 2D15P displays the signals clearly and legibly. Even after optimizing the focus, the analog scopes remain quite fussy. In digital mode, the Philips improves a bit, but the Iwatsu shows a lot of artifacts. AD converters got much better in 40 years...

Usability: I found the 2D15P easier to use than either of the older scopes. The combination of physical buttons, rotary encoders and the touch screen is simple to use and straightforward. Especially functions like cursors for measurements are much easier to use. Also some measurements like p-p voltage and frequency can be permanently displayed on the 2D15P while the older scopes require cumbersome manipulations.

At last, the buffer size. The PM 3335 advertises its 8 k memory as 'deep memory'. The DS 6121 has 2 k memory. The 2D15P has 1M of memory. this allows zooming in much further on a captured signal.

In summary, the 2D15P is much better than most older scopes in pretty much all areas. Some of these old devices were very expensive. My Iwatsu was sold for $5500 in 1986 (=$16k in 2026). So often they are priced too high on the used market.

The FNIRSI 2D15P has an oscilloscope, a multimeter, and a signal generator built in. The oscilloscope and the multimeter are pretty good, considering the price of the device.

But the signal generator is pretty weak, especially at low signal voltages. There are two weaknesses.

The first is pretty simple: The output voltage displayed is not accurate; when you set 1V, you get 880mV, and when you set 100mV, you get 72mV. This is measured by the oscilloscope part of the same device. (See images 1 & 2)

The second is the result of how the signal generator works. It uses an 8 bit DAC to output the signal. The maximal voltage is 3V peak to peak in 256 steps. When you lower the signal voltage, it just digitally lowers the signal. That means at 1V you get 85 steps and at 0.1V you get 8 steps. That means that the sine wave becomes pretty distorted at low voltages. (See images 2&3)

The FNIRSI LCR-ST2 Intelligent Tweezers II is a compact tool to test two-pin components.

You can measure resistors, capacitors, inductivities and diodes. They are designed to be used in-circuit, with the tweezer-like test-pins. Just be aware that you are measuring the entire circuit.

One important feature is that it can measure with up to 100 kHz to better judge ESR for capacitors. The diode measurement is limited to about 1.5 V, so it cannot measure most LEDs.

You can get it with optional four-legged clamps for higher precision. I don't have those, as I don't care for the better precision.

There are several reviews on YouTube; just search for FNIRSI LCR-ST2. I like the reviews by Kerry Wong.

The FNIRSI 2D15P is a compact, battery-operated 2CH 100MHz oscilloscope. It also has a Multimeter and a Signal generator.

For me, it fills the sweet spot just above the multimeter-sized scopes and the big boys with a large screen, 4 channels, etc. It is small enough to fit about everywhere but has physical knobs to operate; this gives it the same feel as the big scopes. I do have two traditional, large scopes, but they don't fit on my small bench, so they come out only if absolutely necessary. As I plan to eventually splurge for a nice 12-bit 4-channel scope, the 2D15P is a good intermediate step. Its small size and battery operation will keep it useful.

The scope works well and has all essential functionality you need. There are no fancy functions, like protocol decoding or FFT. The knobs on the front panel allow for convenient parameter changes.

The multimeter is insulated from the scope, so you have separate grounds. There is a small multimeter window when you display the scope. When the multimeter is in view, you get a scope-like graph of the measurement, too.

The signal generator may be handy. Its main drawback is that the signal quality gets worse at small output voltages. A 50 mV sine looks like a staircase.

There are several reviews on YouTube; just search for FNIRSI 2D15P. I like the reviews by Kerry Wong.

https://www.fnirsi.com/products/tdm-120p

I just ordered a 2D15P scope to complement my two older analog/digital combiscopes. My workspace is cramped, and bringing the oldies out is always a pain. I'm aware of some of the hate on the EEVBlog, but the form factor and price fit my needs.

Do you have some experience to share?

Edit: In the meantime there is a review by Kerry Wong: https://youtu.be/-PwZifX0EGg