When did they do that test?
I'm sure there's the odd, rare beastie available at the £100 mark that might make a usable tablet for those with limited needs, I think looking at tablets from around £140 - £210 is a sort of good range for budget tablets. Tablets at around the £100 mark or less, tend to be seriously compromised, one way, or another, compared with the things they will be measured against (ie type of touchscreen, hardware / CPU, battery life, real world performance).
When I was deliberating, I'd had a look at deals posted on hotukdeals, and comments, and then considered what type of developer community was supporting software or rom development / implementation for the tablet. But in fairness, that was because going back a while, plenty of tablets were being sold with 2.1, 2.2 and 2.3 versions of Android - which if you listen to many, are unusable and unwieldly in todays world of at least Honeycomb or ICS - so developer support was good for 2 reasons, really - 1) there was sufficient that had bought it and cared enough to bother doing any software development / porting for it 2) if you listen to others (before you've really had much exposure to it) anything less than Honeycomb is pointless.
For many of the budget tablets suggested in this thread, though, and they're already running ICS, so whether there's probably not the same degree of developer focus or need. And in regard to my other point, I find my Android tablet perfectly usable, fast, smooth, and rock-solid on a tweaked 2.2 implementation.
It does seem something of a minefield at the budget end of the market. I get why some would say spend plenty and get a known quantity. But then that comes back to a point I made earlier. If I had to spend loads on a tablet I simply wouldn't have bought one. But what I would say, is that the £150 I spent on a budget Android tablet 8 or 9 months ago, was money well spent, because I've not regretted it once, not regretted having bought budget, and had great value and use from it.