Well then it comes down to what you are going to be using it for and what you feel more comfortable with.

Obviously, the 4" is more easily concealed where the 5" has better accuracy at long ranges because of the larger space between sights.

i like the look of the 4'' better but i think the 5'' will have more accuracy at long ranges

I agree with Baldy. It really depends on what you're using it for. If it's going to be range only, than the tac might be the way to go. If you're going to CCW the gun, then you may want the service or even the SC. I carry a XD-40 service almost daily and it works well. But there are times I wish I had a compact model.

No need to post in two separate areas, we'll read it.

~ got a 4 in a 45 & it works WELL for me. It's not bad for CCW except for the Florida summers ... but if I wear an XL tropical/Hawaiian type shirt it works great! I know, I know those shirts are goofy but the Tropical prints are PERFECT camouflage that breaks up and hides "any" print...

It will be for home defense and a range gun mostly

Originally Posted by viper101

It will be for home defense and a range gun mostly

Then in my opinion I'd suggest the 4" model. I just purchased the 5" Tactical for competition purposes. One minor note, and it may not be a big deal to you. The 4" model has a two piece guide rod and the 5" is a single rod. In my area you can find the standard size service model on sale all the time. The Tactical models are harder to find. By the way, my Tactical model purchase is my first Springfield XD. It is very nice. So nice, it may be used more than my Sig. Maybe...