I also lean on MD1 it's a tad more stable but the tips is also not as pointy as ST1.
Some things that ST1 got that the MD1 doesn't are selective secondary parameters.
On the ST1, you can push in the toggle switch with a long push, and jump between the secondary values on a given reading, Q, Z, X, D (from +20s
https://tinyurl.com/mty2ye5k )
The back is also magnetic on the ST1.. Easy to hang on anything metal (there is a small metal sticker-sheet incl. to hang it at any given place of choice).
Got 3 of these budget LCR Kelvin AC tweezers.
*QP-LINK 1S, *Zoyi MD1 and *Fnirsi ST1 "side by side" to give an idea of the size.
QP 1S is quite a bit more expensive, and it shows in the alu build & design. It's more than double, at $48 delivered (incl. 25% EUVAT/DK), but it also got more features... like a 0.1 V test mode, which can be quite useful for keeping semiconductor junctions off, avoiding latch-up, or damaging fragile ICs, while also reducing core saturation in small inductors and preventing inaccurate or false readings in nonlinear or sensitive components, like ceramic capacitors or high-impedance parts.
It’s also worth noting that the QP LCR 1S has a 100 kHz measurement mode that, alongside 0.1V, can help highlight parasitic effects & frequency-dependent characteristics, which could be useful in real-world high-speed or analog designs.. QP-1S also got a 120 Hz mode, which neither MD1 nor ST1 has.
That can be handy for checking parts used in full-wave rectified 60 Hz power supplies, like electrolytic capacitors and other power components, since it reflects real-world conditions like AC ripple & line frequency, it can help you get more accurate readings of capacitance and ESR..Especially in power, audio, and low-frequency magnetic circuits.
QP-LCR LINK1S will also will do/measure DC voltage which I personally find handy to have in a small LCR tweezer, up to around a max of 16V* (if I recall correctly*) and it support higher tolerances like 10.000 count across the full range and it got an accelerometer that will flip the display according to your orientation, or you can user-select in the menu, but it could be that QP LCR 1S is out of production here in 2025, as very few listings last time I checked and prices were significant higher, so perhaps down to "old stock".
Zoyi MD1 got the biggest gap of the three tweezers (highlighted below)