The HKC wired and wireless systems are what we use and are very good system either way,wireless sensors about 45 euro wired sensors about 10 euro.
If you are changing you would be best getting the HKC 8/12 wireless panel as you can use both wired and wireless zones,this is handy if you want to alarm a garage that has no wire fitted.
I have fitted lots of HKC alarms and would not be keen on using any other.
The Aztec stuff was shocking bad as far as I know HKC bought Aztec for there sensor and just to scrap the rest and take them off the market.
The SMS text card is handy but I think Eircom are scrapping text so that will be soon gone.
HKC have a good App but it's 6.99 and they charge for there cloud service on the App which I think is crap after paying for the App.
Not sure about the Yale stuff I'd say there ok as a DIY job but I'd not have it in my house,I'm in the trade about 15 years now and it's one or those things,ya get what you pay for.
HKC is expensive but it's solid,I never had one faulty sensor and only had one faulty bell box so in 15 years that's not bad.