MH choices are typically governed by 2 things: How you will use it and the depth of your pockets. Since most buyers (even ones who try) don't typically buy your last motorhome first, know that whatever you buy, if you change your mind later it will cost you a lot of money.
Are you going to be full timing and/or travelling and driving a lot? Or will you be doing a lot more short trips and typically a weekender with a few extended weeks? What's your budget like?
If you will make a choice based on engine noise alone - be prepared to pay for that.
As a rule, gassers are more noisy. You are sitting on top of the engine and tranny and it's literally inches away under the "doghouse". Some units are better at insulating than others and it's not always based on brand. It could be the day of the week it was built. There are aftermarket mats you can use as sound deadening. Our MH is about as entry level as it gets. But it's actually pretty quiet for a gasser - until you climb a mountain and then it's pretty loud. But We don't full time and I had a small budget so the MH fits our needs perfectly.
So really it comes down to what you want in a MH and what you want to spend. You will spend more on a DP - In up front cost as well as cost of ownership. But a DP travels better for longer trips, rides nicer and is much quieter. But if you don't have a need for all that then you are perhaps spending more money than you have to. Unless you have deep pockets and don't care. At the end of the day, you get what you pay for. But don't pay for what you don't need. Unless of course you want to.
Plenty of folks out there with very nice gassers doing a lot of travelling.