where to put the 6x9's.... Options

[e30og]

SO just started doin some work to the sound system (factory 6 speaker). already have the head unit installed (so easy on this car, makes me cringe to think how easy it is for a robber to....) and looking to replace the speakers. was going to put 6x9's in the rear (Ive had from another car) and make a custom mount found here:

http://www.celica-club.co.uk/wiki/index.ph...9_rear_speakers
(props to whoever put that up)

since this is taking a while to cut and fashion mounts, in the meantime I went to work on cutting the factory 8 inch door speakers and screwing on 6.5's into the cut factory speaker shells, then i noticed one of the 6.5's I have (have had for 3 years) are blown the glue from the cone is coming off. cheap sony **** . Well, it got me thinking, If I have to go out now and buy new 6.5's, why not keep the nice rear angled, custom factory mounts and just put 6.5's in the rear, and then "adjust" the front door speaker shells to fit the 6x9's? this will save me the hassle of making the custom rear mounts

anyone have experience/input for this? I cant really think of a reason why not to have 6x9's in the front. (I also plan on throwing my sub in, but thats later when i have more time) or would it be better to still keep 6x9s in the rear?