Unless you decide to go with an induction cooktop, I would definitely get gas. Cooking with gas burners gives you so much more control than electric. Whether to go dual fuel is a bit more of an issue particularly since it costs a good bit more. Some people prefer electric ovens for baking but a good gas convection oven will bake just fine and will actually be better for roasting meats. Also, a gas broiler is much better than an electric one. I have an all gas range and am quite pleased with it.

Consumer reports examined dual-fuel ranges and found them not worth the extra money, overall. They recommended going all gas or all electric, depending upon preference and availability of utilities/prices. All gas is typically the most economical, if you have natural gas available where you live. On the contrasts between Bertazzoni and Bluestar, we have had some great discussions here. I am familiar with both because they both offered reasonably priced ranges in the 36" size we were looking for. I was sorely tempted by the Bertazzoni range. In my opinion, from the perspective of simple loveliness, the Bertazzoni range is the winner, hands down. It is an example of perfect proportionality, clean, modern, lines, and quality construction. They also have a good reputation among owners and have few drawbacks, a smaller-than-American-expectations oven being the chief detraction. The older Bertazzonis also had some kind of idiosyncrasy with the knobs that some did not like, but I think they changed that. In any case, you will likely really enjoy a Bertazzoni. Unless you are a Bluestar person. Bluestar people are folks who gravitate to restaurant ranges. The whole top of the Bluestar, minus the stainless front driprail and the peripheral trim, is made out of coarsely enameled cast iron. It is REALLY heavy. Pot-bangingly heavy. If something spills or boils over, it falls right down on the burners and from there down to a huge drip tray that you line with aluminum foil and clean out once and awhile. You can put the entire top of the range in the dishwasher if you want. I even run the burners through the dishwasher, ignitors and all, when I feel like it. I think the Bluestar is not as lovely as the Berta. It is more stodgy and muscular, and I don't think it has the elegance of finish one will find in a Wolf or Capital. But if you like cooking on big fire with open burners and a cavernous oven with the hottest broiler you have ever seen, then you should look at a Bluestar. So you can tell my Bluestar bias, I hope, and temper this recommendation with your own requirements and priorities, which may be markedly different from mine. But if I were looking for a range right now, I would be keeping an eye out for a deal on a 36" Bluestar RCS that I could upgrade one burner on to Ultranova BTUs. That is exactly what I did and I couldn't be happier with the result.

I have a Wolf AG. I had a brand new Viking AG previously and the oven was terrible. It could not hold an even temperature, the temp was off when tested with a thermometer, and baking was very uneven. The Wolf AG has not been a problem in that respect. Baking has been even, temps are consistent when checked with a thermometer, and I am very satisfied with the oven overall (no blue porcelain on the AG either). I also love the broiler on this oven and don't know how the electric broiler on the DF would compare. I have only used the convection feature once, while baking cookies. I actually think cookies bake better without it, and it seemed to blow crumbs about in the oven. My oven ignites easily, but they have changed the ignitor on the newer AG ovens so I can't honestly comment on that. I agree with ctycdm, don't let the Berta experience dissuade you from AG. My ancient pre-remodel gas oven was good, too.

A gas oven has more ventilation so more heat to your kitchen and the moisture from the combustion of gas and what you are cooking is removed leading to drier conditions in the oven. This is great for roasting because the dry air movement promotes browning. Electric ovens tend to be less ventilated so hold on to the humidity and better for some baking. Convection fans increase air movement so that you have drying of the surface of what you are baking/roasting and you have increased heat transfer. The drying, browning is nice to have if you have an electric oven. In some ovens, the fans have two speeds with slow for baking and fast for roasting. Few use and care manuals mention this but you can hear the fans change speeds. The increased heat transfer will preheat the oven a little faster and more evenly. It will also cook your food anywhere from 10-30% faster. Depending on what mode you are using the increased heat transfer can change the dynamics of the way something cooks because heat which is "evened out" is brought in from all directions rather than more from the bottom and radiant heat from the sides of the oven. This might change the way a cake bakes. Another part of ovens to consider is if you want "true" or "European" convection which is an electric element around the convection fan. The idea with this is that it provides a more even heat when the oven is full. These are found mostly in electric ovens but Bosch and Frigidaire also have them in Gas ovens. Ovens can be a little more complicated these days and with that there is more need to research and match your cooking style to how these ovens work. There is a little learning curve to using convection. I don't use it for everything and sometimes I only use it for part of the cooking time. For a cake I might start without it and then after the cake sets, I might use it to add a little browning if I want that. My DIL just bought a Bosch 800 series gas slide in range with the convection element and she really likes it so far. I haven't had a chance to cook with it but hope to soon.