yes, they are both 12V... and this is the only common feature.
Color aka "color temperature" is often different. In theory, if it says "warm white", it should be same color as incandescent bulb, but in reality it can be whiter or yellow-er.
Wattage/brightness is different from regular 12V, and again, the range is wild, in the LED case. The measure of brightness is lumen. On the average, incandescent emits 13 lumens per watt, LED - 40 lumens per watt. So if you have 12W bulbs in your rig, this is 156 lumens per bulb. If you want to replace it with same brightness, you need to look for LED with ~ 100 lumens per " flat board", not 156, because the "board" emits all the light down, while your regular bulb emits about half of those 156 lumens upwards to the ceiling. So the flat board" with array of LEDs is more efficient than the LED array made in a bulb shape, though the latter also exist and cost more. Boards come with arrays of 9, 24, 36 and 48 LEDs. The more LEDs - the more watts drawn and lumens emitted. Chinese makers are not very accurate in providing the lumens numbers, so the result might be brighter or dimmer than you want.
To confuse you more, the brightness also depends on the color temperature, i.e. of two LED arrays with same shape and same amount of lumens the one that is whiter, will feel brighter. Despite same amount of lumens. Again, Chinese makers are not accurate in providing color temperature numbers (i.e. whitish or yellowish). So the result you might like better than your old 12V bulbs, or not at all.
PS: all the above is true for LEDs installed by RV shop. It will be made in China, only sold through US retailer. It can be brighter than you like, or dimmer, or color not to your taste.
