By quite a margin, the Sony is the best turntable. It’s Sony first, probably Technics second (but see my later warnings about this), and Dual (a much older design) third. Or to be more blunt, Sony first, daylight second…
Given similar quality cartridges (and the Sony will match a very much wider range than either the Technics or Dual), the Sony will always sound better. For a start, the tracking error is virtually nil with the Sony (due to linear tracking), and the active damping means far lower inter-modulation distortion (IMD) due to the much more damped low frequency resonance. The Sony Biotracer electronically-damped tonearm is hugely superior to the tonearms on the other two. The Sony also uses a very superior base material, the Sony SBMC (Sony Bulk Moulding Compound), which is extremely non-resonant (although the Technics is also pretty good there using a combination of conventional materials, to its credit).
So it’s Sony (particularly given the huge superiority of the cartridge fitted), followed some way behind by the Technics, followed by the Dual, although the Dual has a far better cartridge fitted than the Technics SL-1200. In terms of ‘upgradeability’ it’s the other way around – it’s harder to upgrade a turntable that’s closer to perfection, although I can't see why you’d pick upgradeability in preference to better sound (assuming similar prices)!
I should also point out that the Technics is fully manual – a pain in the neck for a home turntable (particularly if you haven’t used a turntable before), while the Sony and Dual are fully automatics. That means far less chance of scratching records, or wearing out styli due to dozing off while a record is playing.
I’d also be wary of the Technics, due to the fact it has a DJ cartridge fitted – plenty are used professionally, so while it may look nice, that doesn’t mean it hasn’t received a hammering from pro use. While spare parts are easily available to fix it if there are faults, that will cost extra. In its favour, the Technics will be much newer, but if it’s been professionally used, that may not be much of an advantage in reliability.
The only real advantage of the Dual 1229Q, which uses the rim-drive method of platter drive, is that it has three speeds, if you want to play older 78rpm records. It's just not in the race otherwise, IMO - it's a much older design, and the inferior specs and materials used show that. It will definitely sound the worst, given similar-quality cartridges.
In cartridges, it’s the Technics P205C Mk3 cartridge (the newest design and most expensive model), followed by the Shure Hi-Track (late-60’s or early 70’s hi-fi design – depending on which exact cartridge it is – elliptical or conical stylus, depending on what’s fitted), followed a long way behind by the Shure M44-7 (an early-60’s cartridge, widely used by DJ’s these days, rather than as the hi-fi cartridge it originally was).
The Technics P205C Mk3 cartridge was a great cartridge. With a tubular boron cantilever and exceptionally low tip mass, and a 0.2 x 0.7mil nude elliptical stylus, it was probably one of the best MM cartridges ever made, and tracked at 1-1.5g. There were few with such low tip mass (although a lot of manufacturers never published tip mass specs, so some may have been even better than the beryllium-cantilevered Yamaha MC’s currently leading the field in my list of lowest-known tip masses), although a few used better tip shapes. However, it should be mentioned that it will be hard finding an original stylus - even the Jico SAS stylus available for some models of Technics cartridges (not sure if it's available for that one) have solid boron cantilevers, and so probably heavier tip mass, evn if the tip shape is better.
The Shure Hi-Track cartridge could be either an M91 or M95 series (both were known as Hi-Track) – that’s why I can’t be specific on exactly when it was designed (M91 late-60’s V15 Era 2, M95 early-70’s Era 3). In the best forms (M95HE, followed by M95ED, then M91ED and M91E) they have either a nude hyperelliptical (M95HE) or nude elliptical (M95ED/M91ED) or bonded elliptical (M91E) stylus tracking at 0.75-1.5g. The M95ED, M91E and M91ED were second behind the relevant era V15 cartridge in the Shure line when they first came out (discounting the previous era V15’s, which were usually sold alongside the latest for a while), and they could also be fitted with conical styli. The M91ED was a later upgrade for the original M91E, due to a better nude-mounted stylus for slightly lower tip mass and improved tracking.
The Shure M44-7 is a heavier tracking (1.5-3g) cartridge with a conical (or as Shure refers to it, spherical!) stylus which is strong enough to resist the heavy handed treatment dished out by DJ’s, by using a very strong cantilever (not designed for low tip mass), and which puts out a huge voltage output, probably by using a larger, heavier magnet, which also doesn’t help tip mass. It’s been designed for heavier tracking and cantilever strength, and high output, rather than to provide the best hi-fi sound, sadly.
The M44-7 can be upgraded by using the lower tip mass elliptical hi-fi VN2E (V15 Type 1), N55E or N44E stylus, or the conical N44G stylus (or to be exact, seeing that they are no longer made, aftermarket equivalents, such as those from Jico) to be better sounding. However, it’s still an early-60’s design that’s been around since then (V15 Era 1), and was superseded by many later model better-sounding Shure cartridges, including the Hi-Track series.
