Just been reading your posts, There's pros and cons to each side of argument whether to use single or multiple agents. I am a property agent myself and have been for 5 years or so in Dubai. Dealing with brokerages/agents can be a nightmare, i've seen it time and time again, the fact is, if an agent has exclusivity to a property, its gold to them, because the only way it can be sold is through them. It will guarantee them a commission fee, so it stands to fact, that they will do anything not to return the keys. A bonus of only using one agent is it helps sell the property at your expected price but you should expect to wait a little longer due to the difficulty of only one agent advertising against the other several thousand agents currently in Dubai and marketing in Dubai is not exactly easy. It's a very dog eat dog market amongst agents in Dubai, as most only get paid commissions and not salaries, hence the very bad attitudes.
On the other hand having several agents dealing with your property, advertising prices will fluctuate between them and you will get all sorts of prices offered for your property which doesn't really help and wastes a lot of time, even sometimes resulting in your property becoming lost in the market (what i mean by this is, your property will not be a priority anymore and agents will start marketing it on behalf of other agents in order to make a cut of the commission - something is always better than nothing is a common motto),However on the Plus side of advertising with several agents is you are maximizing exposure of the property through media and internet portals, which results in more offers. It's a hit and miss thing really.
My advice is use one property agent if you are living abroad and need someone to represent your property in Dubai on your behalf, someone you can trust, someone may be of same nationality to yourself, so you can build a good relationship with them. Stay in touch with them and meet them when you are in Dubai even if it's not about business. A good trustworthy agent will make the effort to stay in touch with you consistently and update you with both good and bad news regardless (i.e price fluctuations, potential viewings, stupid offers) indicating that your property is priority on their books, even if it's a message on whatsapp once a week, it shows they want to help and shows the attitude of a good agent. If you are living locally, take advantage of several agents, as you can stay close to any action taking place and keep your finger on the pulse, yes you will be bothered a lot more but atleast you know what's going on.
In regards to dealing with just one agent and trying to find one in Dubai take it from me, iv worked for very large reputable broker firms in dubai and also some smaller ones, don't be taken in by the company names or flashy websites, agents are still agents regardless who they work for. Iv seen good and bad in big corporate well known companies and the smaller brokerage houses.
Being an agent myself, i only work with a handful of agents that i know quite well in terms of reputation and experience, i'll be honest, i am a little biased as i am british myself, i only really like to work with similar western nationality expact agents, because i can communicate and relate to them better and they very rarely let me down, because we have mutual expectations. It seems to work for me, so am sure it will for yourselves as well