Among the RE 350s, you can consider the Hunter / Bullet / Classic models for their comfortable ride, neutral ergonomics and smooth as well as characterful engine. In a similar vein, the Honda CB350s also warrant strong consideration for similar reasons. 

All the Harley-Davidson X440 models have a similar riding experience and only differ in terms of features and design, so pick the one you like the most. 

Lastly, we would also recommend you take a look at the Triumph Speed T4 and Triumph Speed 400 as they offer great performance and quality at a reasonable price. 

Take a test ride of all the bikes you shortlist before you decide. 

We would advise you to look at other options than the Royal Enfield Bear 650 because we found the rear suspension to be very stiff in our time with it. This means that on less-than-perfect city roads, your back will bear the brunt of the bumps, which won't be ideal given your long daily commute.

Instead, we would recommend you look at the Royal Enfield Himalayan 450 because it has much better suspension comfort and will have exciting performance while also fitting in your price range. 

If your heart is set on a 650cc bike, then the Royal Enfield Interceptor 650 is the best bet for city use with its supple suspension, neutral ergonomics and creamy smooth engine. 

Take a test ride and decide before you buy. 

Since you are used to a good amount of performance, we'd suggest you move to something like the Triumph Speed 400. This bike will meet your needs of having a comfortable riding position as well as a reasonably low seat height. 

There are more comfortable options available, but almost all of them are adventure bikes with relatively tall seats. If you can get along with a taller seat, we'd recommend options like the Royal Enfield Himalayan 450 or KTM 390 Adventure as good replacements for your Aprilia RS 457. 

Of the options you've shortlisted, the Royal Enfield Himalayan 450 will be the best all-rounder with good highway manners, plush suspension for rough roads, and it's usable inside the city too, although its weight and general size need to be kept in mind. 

The Meteor 350 and Triumph Scrambler 400 XC will be better in the city than the Himalayan, but out on the highway, your comfortable cruising speeds will be capped at 80-100kph. Take a thorough test ride before you decide.

Since you've cut your teeth on the Himalayan 450 for quite a while now, stepping up to a twin-cylinder offering like the Himalayan 750 or BMW F 450 GS is a good bet. 

We would recommend a thorough test ride of both machines once they are launched, and would also advise you to wait some months after their launch before making your purchase. 

Adventure bikes are a great option for a one bike garage when you need to do long trips, especially at the lower end of the market. We would advise you to pick between the Royal Enfield Himalayan 450 and the KTM 390 Adventure duo, depending on your needs. Both options have great comfort, strong performance and superb comfort, so take a long test ride to see which one suits you best.