Welcome to the forum!
Like you, I started on a Masterbuilt electric smoker with an Amazen pellet maze/tube. It made good food and allowed me to find a new hobby.
I jumped into the pellet game last summer with a Blaz'n Grillworks Grand Slam. It does everything the MEB did, only better!
One advantage of a horizontal type smoker geometry that I didn't realize until I got the GS is the ease of accessing the meat. It is much easier to open a lid and have full access to the meat. You just can't get that with a vertical type smoker. Makes loading, turning, spritzing, and saucing things much easier.
I only have experience with my GS pellet grill, so I can't compare it to any others. It's in your price range and can be equipped with an insulated lid and additional shelves. But there are many grills on the market that have the features you want. So the research you are doing will pay dividends.
Good luck and be sure to let us know what you decided on.
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