bubble vs spray etch pcb

So i have a acrylic tank about 1.5x10x10 inches that I use for bubble etching. I pipe in air using a nail-station thing I bought, its basically a quiet little compressor, which I connect to some PEX tubing with a buncha holes drilled in i, which sits on the bottom of the tank. I just have some heating strips that are adhesived to the side of the tank and I use a variac for temperature control. 
I have seen spray-etching machines. 
I am interested in small geometries, like TDFN parts and such, in designed mixed with large geometries (i.e. to-220, DIP, DDPAK) to make full pcbs that have power and (large) signal stages. I am also interested in home made RF/microwave PCBs.
I noticed that getting the etch right with the 0.5mm pin pitch on a big PCB is kind of difficult, on a large PCB I don't have confidence the process will work. Sometimes I need like 3 attempts, careful baby sitting, and sometimes I put masking half way during the etch to prevent excessive erosion. The boards I work with are like 6x9 inches.
I do my exposure using sodium silicate, NaOH and water on MGchemicals PCB.
I don't have a light box and I was instead putting it under a bench magnifier fluorescent ring light. I plan on building a exposure box with some LED strips (will warm white LED work?), but I also have seen some designs for rotary or spray etch machines.
The other upgrade I have planned is to make the bubbles smaller, using something like a 0.3mm drill, right now the holes are probobly made with something like a 1mm drill bit.

Do spray etchers offer significantly better performance in this situation?  Are they worth the trouble? I have not been able to find side by side comparisons of bubble eched vs spray etched pcb.
I don't care how long it takes, just which method has higher quality* I mean so long I don't get undercutting