hello. I've recently purchased a commercial premises. Got a good pyronix alarm and dialler already in there. The pir,s look a bit yellow and dated. Was going to replace them. Was looking at the dual tech ones. Microwave and. Pir in one. I was looking at the bosch bluline and the pyronix ones. Is there any out there which is better than others. Or something that I can just swap over easy ? Many thanks.