There is much talk of the Sellholm M45/6/7 short-shifter, and the copycat product available via AliExpress. This guide is intended to give you a clear overview of the differences between the two products. At time of writing:
The Sellholm Tuning shifter (link) is around $300 delivered.The AliExpress shifter (link) is around $100 delivered.Comparison
The biggest difference and the one that most readers will care about most, is that the Sellholm shifter can be purchased with a 15 degree bend above the shifter ball, along an axis that is about 45 degrees diagonal to the centreline of the car. For a 240 at least, this is basically where you want the shifter to be. This moves the lever knob towards the rear and right side of the car. Without the bend, the shifter will sit extremely close to the centre dash when in 1/3/5 gears. The AliExpress shifter is only available with a straight lever. This means if you want to have the shifter rest in a similar position to factory, you will need to tear it down and use a torch to heat it up and bend it yourself. Whether this will get good outcomes, I can't say, but the shifter lever itself appears to be some soft steel, and is extremely sturdy, so probably it will work fine.
The other differences are much more minor and the sort of things you would expect.
Both shifters come with a set of bronze bushings, however I think only the Sellholm bushings are oil-impregnated bronze (oilite or similar)The bushings are dimensionally identicalThe bushing that sits underneath the shifter ball includes an o-ring on the Sellholm shifter, but that o-ring is not included on the AliExpress shifter. The bushings are identical in size so it is a reasonable assumption that you would need to add that o-ringThe shifter lever I think is a different steel. I wish I had a set of hardness files as I'd be interested to test this.The Sellholm shifter has a very consistent, machined finish. The AliExpress shifter has a less consistent finish, I noticed there was a tool mark (hidden under the reverse lockout sleeve), and the surface finish on the steel is more highly polished (it may even be plated). The Sellholm shifter makes no attempt to do this.The Sellholm shifter also comes with Delrin bushings to replace the rubber bushings between the shifter frame and back of the gearbox. Personally I'm not sure how important this is as the rubber bushings still give you a very firm shifter frame, but maybe with the added stress of a short-shifter this is more importantBoth shifters have an anodised, machined aluminium reverse lockout slider. They are dimensionally identicalBoth shifters have bushings pressed in at the top and bottom of the reverse lockout slider, the only difference here is that the clearances on the Sellholm shifter are tighter than the AliExpress shifterBoth have a Delrin shift knob that is fastened by a 5mm cap head hex screwThe spring that returns the reverse lockout collar to its resting position has a comparable spring rate on both shifters and the feel is basically identical. The one difference I noticed here is that the spring is a looser fit on the AliExpress shifter, and I noticed the first time I tested it, the spring was riding on the edge of the reverse collar.I was able to re-centre the spring by pushing it, I am not sure how often you would have to do that, but it means the Sellholm has a nicer "feel" when lifting the collarSpeculation
I mentioned the bushings appear to be different materials, and the surface finish on the shifter (including the ball) is different. The Sellholm shifter has a machined finish, the AliExpress shifter has a more polished finish. The Sellholm shifter uses an oil-impregnated bronze, the AliExpress shifter doesn't. I think this probably explains the different choices made here, and it may also explain why the AliExpress shifter does not include an o-ring for the bushing that sits under the ball.
With an oil-impregnated bronze, my expectation is that the o-ring will hold the bushing firmly against the shifter ball for a zero-clearance fit. The machined surface of the ball will self-clearance on the bushing and gum the low points of the ball with bronze, creating a low-friction fit with no slop. With the AliExpress shifter, without an oil-impregnated bushing, I expect you may need to occasionally oil and maybe clean the shifter ball to keep it moving freely.
I have also seen people mention having to clearance the bushings around the shifter ball to get everything to fit. I've found this to also be the case with STS Machining bronze bushings for OEM shifters, and maybe this just comes down to tolerances in the Volvo parts, in any case a flat surface and a few passes with some 220 grit sandpaper will sort you out. Just remember the shifter is likely to bed in a bit so if it is slightly firm at first you should find it beds in over the course of a couple weeks.
Neither shifter has a shift pattern on it and for road-legal cars in Australia this is required, something to keep in mind. Probably all you need to do is get a sticker with the shift pattern and stick it on the dash near the shifter.
The shifter has no provision for an overdrive switch, so M46 users keep in mind you will need to put an overdrive switch somewhere else.
Which should you buy?
I think both shifters will perform adequately for most applications. If you can afford the $300 for the Sellholm shifter, I think the fact that you can buy it already with the correct bend for a 240 makes it an easy win for me, along with the fact that I am buying from the business that did the labour of designing the product in the first place.
However, I think if you wanted a cheaper alternative, and especially if you have the means to torch and set the offset of the lever yourself, or you just don't care about how it sits, or you're replacing the shifter in a 740 where (I think) some of the factory shifters do not have that bend in them anyway, the AliExpress shifter is perfectly adequate.