That Acid does indeed look good. It's a solid frame, and the components are of good quality. It is well made and well put together. The fork is a far cry from the old Dart forks they used to put on them, and more than adequate for the trails. I bought Acids for my team to use as duty bikes, back in 2009/10, and they're all still going thanks to a decent servicing schedule.
As Lou says, apart from a lighter frame, the Ltd at the price you list is not much better in terms of spec. It has a slightly better fork. I started off on a LTD, and loved mine, but it was the Race spec one with a Reba, and Stroker Ryde brakes. The wheels were err, strong and robust, but soon and easily upgraded in today's market if you can't get on with them (which is unlikely) . It ain't a beginner's bike though, it isn't as forgiving and won't flatter you until you learn to tame it. With a 72 degree head angle it took a bit of setting up to stop it feeling nervous, but like a thoroughbred flew when handled properly.
The Boardman hardtails are superb value for money, and a slightly different beast. With 120mm forks and a more trail orientated geometry (the Acid is essentially a trekking bike, rather than an XC racer, and the LTD is a scalpel sharp XC bike) it'll be a bit more relaxed, and won't need as much pilot input.