Their motto is "Burpee seeds grow." I have always gotten good results with their seeds. 30 years ago germination was a big problem for me other than with Burpee seeds. I think the science of seed viability has come a long way because I rarely have problems any more. A lot of people confuse GMO with hybrid because of the popularity of heirloom seed. Hybrids are great in my book.
you'll get both sides of the fence here when you talk about GMO/Heirloom/Hybrids.
i try to avoid most of Burpee myself but i have had hit or miss success growing what they have provided for seeds in our area. i always had better luck with the 10-25 cent packs of seeds from American Seed or one of those dollar store brands they carry that are cheap. i have moved away from those since, but i have had luck with seeds from a guy down in Ohio that does a lot of heirlooms. i have also been buying from Bakers Creek, FedCoSeeds, Pine Tree, Johnny's Seeds, High Mowing and a few others that carry heirlooms for some of those more unusual seeds i haven't seen often sold locally.
to me hybrids are not all that bad. they've just been cross pollinated with something to give them a natural occurring gene, resistance or feature already found within the same species in the hopes of naturally improving the offspring. it is hard to save seeds from hybrids since their resulting offspring may not have the same characteristics in the next generation.
GMO on the other hand could be genes spliced in from something that might not be from the plant world. and that sort of scares me that tomatoes could have genes from fish. or 2 completely different species of fish have genes added to help them grow quicker and bigger (look up GMO Salmon) :/ there's some manipulation that nature didn't intend to happen.
Both Johnny's and Burpee's sell some seeds that they get from a Monsanto subsidiary. Johnny's sells no gmo, but they do sell something like 20 monsanto owned varieties, some of which are actually heirloom. Now, I did communicate to Johnny's my concern about that and got their standard one paragraph response. So, I communicated with them again telling them how to get over their addiction to Monsanto. They removed me from their facebook page, lol! What I wrote was so nice though, and helpful!
Burpee's. I was on George Ball's blog as a member. Now there is one powerful man! My replies were always what he did not much like, even though some of his blogs were not much what i liked. He removed me from his blog. Lol! That was well over a year ago, so im not up to date with what's going on there. He did sell heronswood, that i know. There is no telling some folks while they want to tell me. Maybe you can.
There are GMO tomatos but Monsanto hasn't been able to produce a superior variety of them so far. The one they produced to resist frost was an outstanding flop. They got it by splicing in arctic flounder genes and ended up with a flounder flavored tomato.
In defense of Burpee, they were some of the early pioneers of hybridizing and still have some outstanding varieties.