While I don't have experience of any of these turntables, nobody else has answered your question, so I'll give it a bit of a bump for you.
For what it's worth, my opinion is that they all look nice turntables. I suspect the Pioneer will feel more robust and be nicer to use - if it's refurbished then it would be a very attractive option. On the other hand, the Pro-jects look modern and have the electronic speed-selection, which is a bonus on a Pro-ject, so no moving the belt with your hand. Reports of motor noise with Pro-ject turntables concern me, but I've no idea whether the X1 and X2 are prone to this - these are fairly new models.
I believe the X1 and X2 are available with Pro-ject Pick-It cartridges that are akin to the Ortofon 2M cartridges (possibly the Red and Silver respectively). You could go with these initially and see how they work out. Otherwise, I would probably fit an Ortofon Super-OM10 to start with. For the Pioneer, which probably has a heavier arm, the AT-VM95E would be a good starting point or a model from further up the range.
