it is difficult to recommend a fire without knowing your preferences , budget or location demands. However, a few pointers may help:
Warranties are a nightmare. You would imagine that if a fire goes down in January, they would be out asap to rectify. Nothing is further from the truth! I don't know of any manufacturers (except Baxi, and I don't think they do fires now, the fire division was bought by Dimplex) who have a sizeable field engineer force. They all rely on local service agents. The procedure is normally that you phone the manufacturer, and explain the problem. If they accept it as a warranty issue they will instruct an agent to visit. The agent generally have no meaningful parts stock, so they have to order the parts from the maker. They will receive the parts, revisit and repair. (A warranty part will come from the maker, and will NOT be next day, and can take a week. Paid for parts are normally available overnight from a distributor.) Sounds simple, but the agent will have their "own" work, an you will not normal be prioritised. I suspect strongly that this why most fires are designated "secondary" forms of heating - so they should not be the sole source, an therefore never an emergency.
Focal point demand you send them evidence of the date of purchase an annual service before even discussing a warranty!
If I supply a fire, I undertake to carry out at least 1st year warranty work independently of the maker, free of charge - I cannot be done with annoyed clients, fed up with the hassle that Makers cause. So my advice is to find a local independent retailer that will look after the fire in a similar way. If you insist on buying online (normally to save a few bucks), try phoning the manufacturers and gaining a feel for their procedures. Even pretend you have a faulty fire, but you are phoning from work so cannot get further details, and try to report a fault. You may be surprise!
Also most makers with a "free" extended warranty insist on an annual service
(fair enough) PLUS a replacement pilot/OSD (ridiculous, they rarely fail, but makers are scared they won't be serviced properly, and cause a failure). I sell Paragon gas fires, an they don't insist on the ODS, but it is contractual retailers condition that the retailer carries out the initial visit in the even of a breakdown. This will cause a problem if you buy it online or from a retailer a long distance away.
With regard to the glass getting dirty, they all will over time, The glass should be cleaned on a service, and most will expect you to clean at intervals during use. So investigate how easy it is to remove the glass.
Dru fires are very goo but more expensive even than Gazco.
If you have a remote control - what is the consequence of mislaying it? Can you turn the fire on or off (most cannot). Are they stupidly expensive to replace? Don't buy a fire that needs Lithium batteries, they are stupidly costly, and some cannot be replaced without an engineer. I am not sure if any still use them, though, but best to be wary.
If you buy online, get an installation price BEFORE buying. Expect to pay an engineer for the quote/advice if you ultimately decide not to proceed with it.
In summary, research but don't buy online. Research your retailer, and friends and colleagues for recommendations on retailers.