...The last one we had was one of the Q series...I bought a 3 burner spirit... it doesn't controls flare up so well, even with the lid down the fat just burns...
David, as you have stated, the smaller chamber of the Q Series is great for controlling flare-ups - one just closes the lid and starves the flame. The challenge can be in dealing with the smaller cooking area.
I have a stainless steel Weber Genesis as my gas grill, which resides outside in the weather. A large Kamado Joe does most of the heavy lifting at my home: grilling, smoking, pizza, etc., but it is wood-fired and the topic of a separate book. Managing flare-ups on a larger grill is definitely a required / acquired skill, but that extra cooking area is soooooo well worth the effort. I cannot address the build quality of the Weber Spirit as I have no experience with one, but the Genesis is built very well and has endured heavy usage.
As has already been mentioned, the spritz/spray bottle is your friend, as is the dual-zone heat control. But there exists an additional tool that I would not be without, especially for meats (which can be the primary culprits behind fat-fueled fires, though olive oil-soaked aubergine will result in the same outcome). I have a large slab of Himalayan salt that sits across the grates at the back of my grill (it cost a small fortune but lasts forever - minus a month or two).
Initial searing occurs at the front of the grill, with yours truly in attendance. Putting lovely grill marks on filet mignon (my personal favorite, for those considering sending gifts), results in zero flare-ups so the steaks first get their gorgeous and succulent patterns and then are moved to the top of the slab of salt to come to temperature (133 F, 56 C for this connoisseur. I also add a small pat of Germany's Meggle butter; there is none finer - mon pere est Francaise and me mum is Irish!) for the filets to finish in, but that is the topic of another book.).
Rib Eye is another issue entirely. With spritz bottle in hand, these flavor bombs are dropped onto a 600 to 700 degree (F) grill (315 - 371 C). It takes all of 1.5 seconds for the fireworks to begin, but light misting keeps the flames at bay, which is all that is needed to allow the desired Maillard reaction between hot stainless and le boeuf du jour to occur. Introduce only enough moisture to drown the flame, not the carne. Addressing the flame, charring has it's place, but not on my steak! Carcinogen issues aside, there is a better place for all our palates to visit and it is definitely this side of burnt. Moving these glorious hunks of flesh onto the salt slab allows not only the salt to do it's wondrous thing, but immediately extinguishes the worry of the fire.
(By the way, salt is by nature incredibly anti-microbial. It may appear all hideous after an indulgent cook but you must resist the urge to cleanse it - simply scrape the surface with a flat blade and await the next re-heat. The temperatures used to prepare your food will readily dispose any pathogens that may have actually survived the salts' own cure.)
David, you can achieve some of this glory on a Q Series, but I believe you could be better served with a new approach, using a larger grill. Think of all those fabulous alfresco parties you can throw, replete with lavender or rosemary sprigs, juniper berries and persillade. ;~}
