Mcilroy guitars consists of five standard body sizes:

AJ - The AJ is Mcilroy's jumbo size guitar, Jumbo size and a A big box that delivers a deep, resonant tone, volume and dynamics perfect for strumming. Due to construction it doesn’t lack balance in the Treble and mid-range like most other jumbo’s do. It is popular with Session players that need a guitar suitable for all styles and need volume. If you don’t need the volume you might better choose for the A or AS series.  
A - This body size is most similar to a mini-jumbo like Lowden and Santa Cruz style F or Taylor Grand Auditorium Model. Perfect for a mixture of strumming and fingerstyle. Overall the most popular guitar, very comfortable to play, very balanced, with strong tone and sustain to die for.
AS - The AS body size is the Smallest of the Mcilroy guitars, equal is size and depth to a classical guitar, or, If you want to compare it to a Martin guitar, somewhere between a  00 and OM – but with a deeper body and braced in a completely different way. I find this instrument tonally impressive. The balance found in this guitar, the purity of tone and overtones are really unique. The guitar is suitable for many styles, including classical steel string, Celtic folk and blues. Best seller in the UK. It is extremely rich— incredibly loud for its size, - 
AP- The AP is a new model, the acoustic performer, a slim-line body, that is similar in size to the A model. 648mm scale and 45mm width at the nut. More about the guitar when I played it. We love the Martin OM models and sure will find the Celtic answer is equal in quality and typical for Dermot’s style! Test results are very promising. Custom orders for a ASP, ADP and AJP are possible also.
AD- The same goes for the AD, it is new, dreadnought model, and I have never played it. Similar in size to the A-series but with shallow waist and sloped shoulders. I have seen the guitar and it is beautiful. Very suitable for style and genre,  We have high expectations after reading the test results. More personalized comments later.

Other instruments Dermot Mcilroy  builds
MG- The Mando Gazooki, A 8 string Mandolin like instrument with a longer scale length and wider fingerboard to improve players comfort.
G- The Gazooki, a 8 string Bouzouki type of instrument, with similar scale length to a guitar and suitable for many different tunings. DADG, DADA, EADG and EBEB to name a few. Available in three body depths, the GS, slim size 60mm deep, the G size, normal 80mm body depth for Gazooki and the GJ, the jumbo size of 100mm at the tail.

Tone wood appointments:
10-15 Mahogany series-  Spruce (10) or Cedar(15) top, Honduran mahogany back and sides, mahogany/sycamore laminate neck, with bindings of walnut, sycamore, and rosewood.
20-25 Walnut Series - Spruce or Cedar top, Walnut back and sides, mahogany/sycamore/walnut laminate neck, and bindings in Pear-wood, Rosewood, and Sycamore.  
30-35 Indian Rosewood Series - Spruce or cedar top, Indian rosewood back and sides, Mahogany/sycamore/rosewood laminate neck, and bindings in Pearwood, Sycamore, and Rosewood.
40-45 Maple Series - Spruce or cedar top, Indian rosewood back and sides, Mahogany/sycamore/rosewood laminate neck, and bindings in Pearwood, Sycamore, and Rosewood.
50-55 Madagascar, Cocobolo, and other exotic wood Series with the exception of Brazilian Rosewood -  Spruce or cedar top, exotic back and sides, mahogany/sycamore/rosewood laminate neck, and bindings in sycamore, figured sycamore, pearwood, and rosewood.
60-65 Special Figured woods - Model 60 and 65 guitars are reserved for special figured woods that Dermot occasionally gets his hands on. All other features like the 50-55 series.
70-75 Brazilian Rosewood Series - Sitka or cedar top, Brazilian rosewood back and sides, mahogany/sycamore. All other features like the 50-55 series
80-85 Brazilian Rosewood Series  with full abalone Soundboard inlays and Celtic knot Fingerboard inlays – All other features like the 50-55 series.