Kyushu, arguably, is best explored by car, as the Shinkansen really only connects Fukuoka with Kumamoto and Kagoshima, leaving a lot of other interesting attractions off the bullet train grid. Such as Nagasaki. As far as my research went, this hotel is the only one in central Nagasaki that offers free parking. Plenty of free lots during our stay. Some were roped off, which I presume is a measure by the management to reserve spaces for staying guests (there are also conference and restaurant facilities on site).
The property is conveniently located near Glover Gardens, Chinatown, Dejima and the jetty from which the Gunkanjima excursions depart (all walkable within 5 to 10 minutes).
The hotel also treats IHG members quite well. Even though we had basic status on the programme, we were upgraded to the top floor (which, even though there isn't a club lounge or any kind of view, is normally a paid option!).
Concierge was helpful in making restaurant reservations, and offered to give us directions (which we declined as we had Google Maps).
On the downside, the hotel was supposed to have been renovated just last year, but the decor still looked dated. Very spacious rooms though (booked a deluxe twin room).