three

To address the OP directly, I've owned four Spectors, all US models, and still own two, both Spector Shortys. For context, I haven't owned a Czech or any other model. Both of the long-scale basses (NS4 and 5), now sold, had deep profile necks that were frankly too large for me to play comfortably. The basses were built and finished to a superb standard - truly on a par with or superior to anything else that I've played (including Wals etc.). Solidity and stability are assured with the US models in my experience. The gloss sprays were also world-class - the ultra amber 4 was an instrument of rare beauty, and the water cured redwood 5 was uniquely lovely. Electronics (HAZ and EMG) were very hot, though not to my personal taste. The basses were sold as they were heavy, the balance and ergonomics didn't really work for me, the tonal range didn't really fit my needs/tastes, and the neck profile was a little too much (though as others have indicated, there are options within the US and other ranges). That said, I miss both in terms of sheer build quality and good looks. The two Spectors that I've retained are Shortys and are my main basses - they're both different takes - one with EMG humbuckers and an Aguilar OP3, the other with Aguilar P and J pickups and an OP2. The build quality is exactly the same as the long-scales - superb - the three-piece necks are wonderful. Both necks are fairly slender and beautifully carved: one has the DW 1.5 nut and the other, a standard 1.64. Body carving, tops and finishes are exquisite - perfect really, though both bodies have satin/matte finishes and I tend to prefer gloss. A little strangely, the DW necked bass is significantly lighter than the other. I can't comment on the Czech instruments other than to say that some of them look staggering. If cost isn't an option, I'd go for the US versions, but be prepared for a reasonably heavy instrument with a deep/thick neck (unless you're able to specify otherwise). US Spectors remain my go to for pretty much everything.

This thread is an absolute joy - staggering talent and an outstanding achievement. Wow!

There’s an Epiphone pro version in white on eBay at the moment for £450 – in Telford. Looks decent - item number is: 196752560838

Great choice in my opinion - the Baby Sumo is a really impressive implementation of Class D. I've used a Tonehammer with some success, and a Mesa Subway+ preamp and DI - the latter was really impressive, though they're really difficult to find and are no longer in production. I've used all sorts of pres with the Baby Sumo (Warwick PR40, Monique, SF2) and they sound how you'd expect. I think I read somewhere that somebody had experienced some input gain problems with the Sumo, but I certainly haven't encountered any issues with signal. I haven't used an SBP-2, though if it's a pre that you know and favour, probably worth a try - I'm pretty sure the results are what you'd anticipate

If you can find one - I wish I could - I'd recommend the Mesa Boogie Subway+ DI. I really shouldn't have sold mine. Two DIs (Mic and Line from memory) and real versatility in a well-built package

It's the first I've heard or seen of these - possibly an interesting addition to the Alembic line-up, and something novel (I think) with the extra filter modes. I use an SF2 that appears to have a little more in terms of control/parameters, but I can see the pedal-type form factor appealing to some. It won't make any bass sound like an Alembic, but a useful tool for recording and live use. The Alembic filters (in the SF2 and probably in this box) offer a great deal of control and versatility. On a related issue, I've been playing for decades and have yet to meet an Alembic-playing dentist, though I do know a guitarist that gigs as a consultant gastroenterologist

I live in the town (utter dump) and don’t think there’s any connection between SUYG and Tony - other than optimistic pricing for quite ordinary basses. Perhaps oddly, I don’t know Tony though I think he offers lessons. I haven’t seen him playing locally either. The town’s once thriving music scene crashed dramatically in the late ‘80s (along with its economy as a whole). I might go and have a mooch but can’t see anything that appeals, especially given the prices

If these are anything like as good as the Spector Shorty (no reason why they shouldn't be), they'll be superb if prohibitively expensive basses. I often wonder why the Shorty was discontinued (if indeed it was, though I haven't seen a new one for a long time). The Shorty came in a wide range of configurations, though didn't have the exquisite curves of the NS2 etc. I'd be interested to see the prices, though very unlikely to pay them.