I can't believe how people answer every question with a response that is totally unrelated to the question. The OP asked about Glocks vs. Sigs. Not any other brand or type or configuration or color or weight or concealed carry ability. It was a very specific question dealing with a home defense and practice weapon.
The answer is that yes there are differences between Glocks and Sigs. Glocks are great carry guns but for target practice they are not so great at least not compared to a good Sig. Sig makes some of the most accurate firearms being sold and the P220 often ranks as the #1 choice among all handguns when people have polls on websites like this one.
A Glock will be lighter. A Sig will be more accurate. A Glock can hold more rounds in a mag but you can always buy a handful of mags and make that Sig just as effective or close to it.
There are great differences in how the two operate also. You won't see any single action Glocks (at least AFAIK) while there are lots of single action Sigs. They are generally single action / double action guns actually. For target shooting that makes a huge difference.
In short if you want a gun just for self defense either the Glock or the Sig will do fine. If you want a very accurate target pistol get the Sig. Glock doesn't make target quality handguns AFAIK.
Of course things like ergonomics matter a lot. If that Sig is too big for your hand or the Glock is too small you will want something else. You need a gun that won't hurt your hand when you shoot it because you MUST practice with any SD weapon if you expect it to be effective at protecting you.
Personally I've looked at Glocks with the intention of buying one for concealed carry but I've always ended up with something else because Glocks just aren't made to fit my hands. I do own a Sig P220. For a home defense gun they are excellent as long as you know that walls don't stop bullets unless they're concrete walls or block walls or basement walls (exterior basement walls). I have my Sig right next to me in my desk drawer. But I have pistols all over the place so... I have other brands besides Sig.
Still the answer to your question is yes there are differences and they do matter a lot actually. You should do a lot more research IMO before you make your choice or you can do what us gun junkies do - buy both.
They are both fine guns. They are just different.