While as an alarm it is relatively good, it has such a bad remote control that it really makes it not worth it... the screen broke on the first day from the vibrations of driving (!) just because it was touching the steering wheel... I replaced it at a cost of 70 euros, almost half the total value of the alarm, only for it to break again within a week because it was squeezed in my pocket... this has never happened to me with any other alarm before... its battery needs to be replaced once a month, while after a year the remote's circuit board broke completely and it doesn't even turn on... the only solution is to use the simple one that doesn't have remote notification, but if you're going to use it like that, why pay 200€ and not go for a cheaper model at half the price... it's a shame because as an alarm it has many features and low power consumption...

I have had it for almost 2 months on a new motorcycle.
Positives:
1) It has remote notification
2) It has a strong siren
3) It adjusts easily
Negatives:
1) The remote control turns off very quickly when it beeps, and you can't see the cause of activation
2) It only has one remote control with notification. The second one is basic
3) The battery of the remote control runs out quickly
4) The turn signals do not activate when arming/disarming
5) There is no indicator light for the armed alarm

I don't know if I fell into a bad case, but I have never seen a bigger piece of... alarm. The pandora eumoto is in a different league. Where should I start:
1. The remote. You can't check the status of the alarm without pressing a button that will communicate with the alarm or make some change on the remote. So if the alarm goes off, as a warning not normally, the screen turns off and when you press a button (with the above limitations I mentioned), it doesn't show why it went off. You don't know if it's the tilt or if someone moved it.
2. It goes off for the slightest thing. The bike is just sitting there, not even touched by the wind, and every little while you hear the warning as if someone moved it. I went to see what was going on and it goes off because, as I said, you can't understand from the remote unless it goes off exactly when you're looking at it, and there was nothing. I thought maybe a cat, but after a while it went off again in front of me without anyone touching it or anything.
3. After breaking down the above and trying to see if the sensitivity is at maximum (it's one step before maximum), I went and kicked the front and back tires a few times to see if the warning sound would activate. Nothing, guys. While it can go off by itself, when I bang the bike myself, the alarm doesn't notice. It needs a lot of force to activate. So the sensitivity level is not the issue.
4. The turn signals don't blink no matter what I do.

Cost of purchase and installation 300 bucks. Wasted money. A thousand times better with pandora. What did I want the changes for... Stay away, guys! Don't even get close to it.

It seems like a very quality alarm and its siren is very loud. The remote control is sturdy (its buttons are on the side). I don't have an opinion on the battery yet. The reason I'm giving it a 4 in the rating is that on the YAMAHA XMAX '23 where I installed it, I was informed by the workshop that did the installation that it cannot be connected to the bike's turn signals, so they never flash in any mode (arming, disarming, alarm mode, etc.), which is not what you expect for the value of this alarm.
[I am waiting for confirmation from elser on this and if anything changes, I will come back with an edit]

EDIT: After communication with both Yamaha and ELSER, they confirmed that there was an issue in the past and assured me that it can eventually be connected to the turn signals (in my case, more easily only with the rear ones rather than all four). To connect all four turn signals (front-rear) is (they say) a whole story (a lot of disassembly and removing parts from the bike to run the wires). In the end, at the workshop where it was installed, they fixed it and it works just fine (in my case, only the rear ones were connected).

I would say that it is an excellent alarm!
I have combined it with the perimeter, which I haven't needed much...
It has a two-way control that informs you about anything that happens when the alarm is activated.
The battery in the control runs out relatively quickly and needs to be changed, maybe it could be rechargeable.
In combination with a GPS, it could be a satisfactory option for aspiring thieves, although the best protection may be not to lose sight of your motorcycle!