The Hotel Achat is fairly new and we were most impressed by the excellent staff. However, rooms are pretty stark with very few creature comforts. The shuttle to and from the airport or the Exhibition Centre (Messe), which is mentioned on the hotel website does, in reality, only run at certain times so you better check with them beforehand. It is also not as close to the Exhibition Centre as their name might suggest. That makes it necessary to travel to the 'Messe' as well as the city for restaurants, shopping, etc. A taxi to and from the airport is not the €18.00 as the hotel says but between €23.00 and €33.00, depending on the time of day/night.
In our opinion it is worth to look for a better hotel nearer the city centre and then to use public transport or a taxi to get to the exhibitions. At least in the evenings you won't have to go through the same trouble – and expense - when dining etc. And Leipzig is definitely worth an extra day or two!